I've been looking at this for awhile and, although I've seen some super-cheap pieces of land, the price goes down as the proximity to good employment decreases.
And, personally, I wouldn't want to become a subsistence farmer, way too risky. Not only that, but most small farms are hobby farms that do not sustain people. So, if you want to truly escape, I'd advise the following.
First get the highest-paying job you can and live cheaply. Then invest every dime you can into passive income sources while doing a deep dive into your basic income requirements when your big move happens. Once your PI is at a sufficient level, you can make the move and live on your farm in peace. And if it does happen to make some money, that's just a bonus, but you should never fully count on it.
I've already been doing a variation of this, though without the farming aspect, I'm just going to live in a small condo.