Difference in price apples to apples C2 v C4 (Coupe 5 spd) is about 20%. C2 coupes are hottest pcars right now. You'll need at least $60k to get a sorted driver example with history. I follow the market pretty closely. Lots of polished turds out there. Can't emphasize the importance of a thorough PPI enough. Repairs bills can add up quickly on neglected examples.
This example got bid up to $45k on BAT today and looks like a disaster.
https://bringatrailer.com/listing/1990-porsche-911-carrera-4-12/
If your looking to get into the market in the $40s or so look for a cab. Plenty of nice examples seem to pop up.