We all have our lists of supplies we would buy, once it is obvious things are getting dangerous
Do you have any pre-defined points as to what will be considered dangerous enough to actually trigger the buying of supplies? Boiling the frog creates normalcy bias and tends to rationalization. Your group should decided ahead of time what conditions would signal buying of supplies - otherwise, they will probably be trying to buy them in a crowd who also see the same thing. ( but maybe you can count on your neighbors being so dumb that they still won't do anything even when there is a Giant robot outside their door screaming "Danger! Danger! Defcon 3, 20 Trillion Debt, Lousy candidates! Shredded Constitution! Corrupt Officials and agencies! Mainstream media is noting but govt propaganda arm! Riots in the Streets! Danger! Danger!" Oh wait. That's today's Drudge report. )
Seriously, I thinks its time now. I would stock at least 6 months a person at this point. Maybe three in one location and 3 in the other, but 6 in both is probably better. ( After 6 months you can go and retrieve the well hidden stash) Also get a Berkey filter or similar - wells that are good now, may not always be so, or you may be forced to move off. Just don't mess around with food and water. You know you will need them always. The Mormons keep a year of food.. Much of this can be in canned goods, and you can continue using them- just stock from the back & take from the front.
Its hard to say if a "organized" camp screams "attack". It might also scream "Guys who are armed, know what they are doing, and will kick your A**es. Find easier prey" Ideally with your numbers, you are patrolling/keeping perimeter watch and will intercept anyone before they find your camp anyway. This may be easier or harder depending on the geography.
I have prepped two places - its nice to have options if you can afford to get both ready. It would certainly make sense to stock both with supplies, and have a plan to move or retrieve them once it becomes obvious where you need to be. It took me a while to come to terms with the fact that when the event happens, one or the other place and all of my work there is likely going to be abandoned or lost - unless one of the "trusted people we know but are not too keen on planning...but could be trusted if TSHTF." ends up going there instead of here ( or vice versa) .
If you have to pick one place to prep:
On The 50 Acres...its that a currently working farm? Is it livestock, plants or both? Which animals, Which plants? How good is the well? Is it flat or hilly? Forested? High ground for the area or low? Is it likely anyone would do that? What is living in the pond now? how remote is it? ( there is such a thing as too remote- that was proven in Argentina) What other resources are available around there? What skills? What ideology are the neighbors?
On the 30 Acres -- How far from town is it ? - how big is the town? How good is the well? Is it flat or hilly? Forested? High ground for the area or low? Is it likely anyone would do that? What is living in the pond now? What other resources are available around there? What skills? What ideology are the neighbors?
Which one has the creek? ( Out here a Creek is a flow of water 2-4 feet wide and a few inches to a foot deep. The Eastern definition tends to be much larger.)
Would it be easy to move up or down that flow? Would anyone be likely to do it looking for food or fresh water?
If you already have campers/RVs and vehicles to use for temporary housing, has anything been done to allow for RV hookups of power, water or septic? How good is the well? Does either site have the equipment ( Backhoe) to quickly and easily dig a newer larger septic? I am not talking fancy. I am talking hole in the ground with half Barrels and/or tile. Ideally with a large IBC tote or two set up as the settling tank(s). For the cost of some PVC pipe, conduit, cable and recycled barrels and a couple of weekend with a back hoe you could have a location ready for that influx of people and for way less than 10 grand. Probably around 6k. Yes, you COULD drive the vehicles over to a central location to dump septic, do an outhouse ( you already know there will be a jackass who will insist on using the one in his camper..) , run independent generators , run hoses, etc. Its all about the standard of living you are after, and how quiet you want the camp to be, and how much fuel ( or human energy) you are willing to expend in such activities, and how much risk you want to take. (Hoses above ground can freeze. Cables above ground can be eaten/cut by rodents, or just crimp form ground traffic and so on. Every calorie you expend dealing with these issues is a calorie you will need to replace with food. Ounce of prevention = a Pound of cure. Really you want to be focused on gorwing food and security. Not mending a broken hose for the 5th time)
Centralized power is also a really good idea, even if its generator driven.. Assuming the existence of a generator already on property , a cheaper system of batteries and a decent inverter ( maybe a dual so you can do 240) would be the cheapest central power source. Probably another $5-6 K, but it will allow silent running and be more efficient on fuel since only one generator would charge the battery bank. ( With details on the gen,and how long you want to run silent, I can help design that system, and it could sit on a small trailer, or in a pickup with shell. ) Likewise, a central freezer, fridge ( look at converting a cube freezer- air stays inside when opened - can be more efficient if you use a bucket system to get things in and out and you aren't digging for minutes) Likewise a central kitchen/living area will be conducive to group dynamics and cohesion.
Also look at those hoop houses. http://www.farmtek.com/farm/supplies/prod1;ft_high_tunnels_cold_frames;pgpb01680r6c.html
If you double sheet the hoop and inflate an air cushion with a fan - these can be insulated decently. So for around 7K you can create 2800 sq feet of "indoor" living space - you can expend some energy heating.. It will look from outside as if its for agricultural use - not like a camp, and depending on what you cover it with ( perhaps blue tarps on the North side and leave it clear on the south for passive warmth) you could partition it off into rooms, and perhaps park RV's inside it- which will also reduce the cost of heating the RVs. The "clear" plastic isn't all that clear - it gets less so with age, and a double layer will make it much harder to see though. Perhaps have tarps on the south side you can raise and lower to control the light/heat. A portion of this area can be dedicated to group living. Otherwise you will have issues "Why is it always MY kitchen we use for meals? And they always leave it so dirty, and my camper smells because they always cook that spicy onion dish.." - etc. Facilities used by the camp need to be group facilities and not part of someone's private space ( and as much as possible everyone should have one. Even on Subs they have those curtains in front of the bunks)
In the meantime it could actually be put to agricultural use, and there are actually government grants to help buy such things.
So in summary, I think your major task right now is to get the group to pony up some money for long term food - freeze dried food, and buckets of grain ( these can be made cheaply yourself) and a grain mill. Decide on a property or plan both. Sounds like right now your group wouldn't even know where to assemble if communications were cut. ( and sadly a Russian Nuke attack where that would happen is back on the table. Probably pretty unlikely still, but...its doesn't cost much to talk now while you can, also plan communication drops at both properties. Just a PVC pipe with a water tight lid - you can leave keys, messages, or any other small useful object inside - and then you build a cairn over it or have a predetermined hiding spot. )
Second - get them to at least prepare a plan for doing the expanded septic system, on one or both properties. If you are worried about disease, the best thing you can do is ensure the human waste is taken care of properly, and with as little contact as possible.
The Power system is something that would benefit the current property owner, as they would have power 100% even when grids down, so you might be able to convince them to carry more of the burden ( of course you can also go with a battery less system, but that means the generator will run nearly 24/7 and much of its power will be wasted. Of course a PV system is an even better idea, but now the cost jumps by another 10K or more.
Likewise, a large fuel tank may also benefit the owner of the property, he would use and refresh the fuel and keep the tank ready for when there is no more fuel coming.
What caused the splintering in your group? Is there anything that could have been done to avoid it?