We just discovered this lifestyle a few years before retiring.
To tie this thread into the board's topic -- it costs somewhere around $1000 a month to live this lifestyle, not including health insurance.
Part of our strategy in retiring early was that if we did this for 5 years, we'd postpone dipping seriously into our retirement funds -- and we'd have a blast!
Not for everyone, as living in under 200 square feet can be claustrophobic -- but we have a beautiful huge back yard, and it changes whenever we get tired of it! (And no mowing!)
Dory36