In many places, 5 acres can be had for less than $10,000, and one can build a cob house, a roundhouse, or any one of many ancient, but very energy-efficient and habitable structures. Cheap, industrial-bulk solar panels and a dozen car batteries can supply all of one's lighting needs. Chicken feed is cheaper than buying either chickens or eggs at the supermarket, and a well and one's garden can supply a great deal of one's year-round nutrition.
Initial cost: $30,000 max
Monthly cost: $500 max
This is precisely what two friends set out to do approximately 14 years ago. They're still succeeding in their earth berm house.
No more mortgage, no more landlord. No more paying the man or feeding the system.