There's a lot of conflicting information on how much land you should buy. There are over optimist hippy types that say you can feed a family of four with .25 acres and others that say 10 is the minimum with livestock or 50 for hunting.
On the other hand, if you're attracted to the isolation, it seems like most of the 5-10 acre lots you see are not a great leap from suburbs. they're usually in the big long strips where your neighbors house is only 50-100 yards away on either side.
So, do you buy as much as you can reasonably afford, or do you go with some calculated range? lets say you want to grow or hunt 90% of your food, but you're not that interested in selling anything.