Theres a simple answer to this: You can't. MKIV Supras are pretty rare, especially in un-modified form. Not to mention, the recent drifting/tuning craze has only driven up the prices. Also, Supras were meant as higher end sports cars when new, so they were extremely expensive to buy, which means that most owners either spent tons of money modifying them, or they babied them. So no matter what you do, you're very rarely going to find a MKIV Supra with high mileage and/or in bad condition. The cheapest MKIV's you'll find will be non-tubo automatics, usually 93's or 94's. If you want a cheap Supra, don't dis-count the MKIII's. They're still great cars, if not as good looking. They have a similar engine to those found in the MKIV's (Though the JZ-GTE's in the MKIV's are known to be stronger and more powerful out-of-the-box than the MKIII's M-Series engines). Also, check out the early-mid 80's Celica Supras. These are pretty rare, and pretty cool cars to boot. Classic Old-School Toyota charm! They're slower, yes, and don't quite have the pedigree of the newer models, but they're still damn cool cars! Good luck in picking a Supra! You won't regret it!
Life-long Toyota fan. (I have an