The cheapest way to get your ratings nowadays is to buy the plane, fly the snott out of it getting your time and ratings as quickly as possible, and then sell the plane. In most cases you get back what you spent to buy it, sometimes even a bit more.... so it ends up costing you the gas, insurance, tie-down and instructor. If you do it fast enough you can skip the annual and hopefully avoid some mx costs... but even if it takes a few years, in the long run it's still the cheapest way to get your time and ratings, especially since you'll be trying to do 150+ hours a year at least...