You are ignoring very special cars:
This one especially: C5 zO6... can be had 01-04 ($19,000-$24,000)
1993-1998 MKIV Toyota Supra Turbo... ($17-30,000)
One of if not the most reliable sports car ever built, I in fact know 2 that are pushing over 700whp on single turbo set ups with 200,000 miles on them and stock block, transmission and more. The car pulled more than a 0.93g in stock form and the world record for stock block WHP was 938whp on one of these, an amazing car that you'd be foolish to ignore. You can pick up one for between $17-30,000 in very good shape and probably pushing 500+ whp on a single turbo set up. The build quality of these cars is great regardless of age and mileage. Mileage doesn't matter with these cars, they hold up so well.