It is true that supra's can be a bit pricey to upkeep. But on the other side of the coin, their 17 years old. There is allot that can be done to a stock supra. I inherited my stock 92 7mgte and love every minute of it.. Yes the general upkeep and maintenance must be done anualy, but isent that true of all cars you care about. My 2 cents are this, if you want a sports car that you can aquire somewhat cheaply and are able to invest some time and money into maintaining and upgrading. Then at the end of the line you will be driving one of the most rare sports car in your town. (1500 92 supras imported into the usa, please correct me if my numbers are wrong im just going from memory.)
Oh another thing. you want an import sports car.. 7mgte is one of the most eziest engines to work on. compared to a damn 2001 mitsubishi eclipse spider (what my sister drives)
http://en.wikipedia.org/wiki/Toyota_M_engine <- allot of info on specs here.
or you can just go the ez rout and purchase a honda civic with a fart cannon.
My first car.. btw 92 toyota MR2. manual steering. now thats a car to learn to drive in.