Cheapest land in the US?

Hi all, I know this question is probably asked a million times but I am desperately looking for land to save a USAF veteran friend of mine.

I recently found out my friend is homeless and has been for about 14months after we lost contact for a few years after he moved back from the UK. Now I don't have a huge amount of free cash for this, roughly $20k

I am a carpenter and general builder in the UK by trade, I'm happy to do the work so he can get a place to call home