Never buy on contract, especially from "a friend". Good way to part on not so friendly terms. Save for cash only purchase. Why go into debt when you are practically out of debt. You always have to include the worst case scenario..the unknown-health etc.
Build a house for ourselves, do metalwork, pottery and weaving for sale and trade with work on the side.
I don't mean to be a "downer" but there are tens of thousands (maybe many more no figures) of people with the same skills in my rural (vacationland) state. There are too many "artisans" who just got by before these poor economic times. What level does it really become a business and not just a hobby. Building supplies are up, go figure; even though builders (many of of work) of all skill levels are in heavy competition in their "contracted" prices. Logs have to season as well before a building is elevated, so that takes time with your own harvest. Not a "before winter" picture of reality.
Perhaps rent with option to buy, caretaker with quarters provided. Believe it or not, people do take care of light houses. Might need references. Flea markets bring income with little down. Popular as well. Are you anywhere near the World's Longest Yard Sale? The US 127 Corridor Sale? But "fun" buying will be less abundant with cash being held tight to the chest. No matter what income level.
South central Tennessee would not be my choice, but you go where you feel most comfortable. A support base.
Just my opinion. I am sure all the above have been under on your list made up of Positives and Negatives. If it "feels" right with no reservations..like asking others for their opinions ;), then go for it.
Good luck.