Enough arable land to feed family of 4 can be bought in USA for $14k (and you can buy it outside of US). Add $7k for next 50 years of property taxes.
You can also join Amish communities, if you are religious.
You won't have access to pre-modern supply chain, but you are probably eligible for social security and foodstamps, so you can exchange them for new scythe or something like that.
