Don't buy any 10+ year old European car. Parts cost a fortune, and was was once a technological wonder is now an obsolete electronics nightmare.
Here is a simple but generic breakdown of the experience you'll have with a common replacement part on various cars... Starter.
Ford/Chevy: It'll cost under 50 bucks and you can get it anywhere.
Japanese car: It'll cost $250, take twice as long to remove and replace but it will last 4 years longer than the Ford/Chevy starter.
Mercedes/BMW: It'll cost $450, be on backorder, you'll have to replace some other $300 module with it, and you'll have to pull the engine to get to it.
If you're in the market for a 1000 car, get a domestic. Of the ones you mentioned, the T-Bird is the best. The Ford 3.8 is simple, lasts a long time and parts are cheap. The AOD auto tranny sucks balls, but works OK with the 3.8's meager power. If it's a 302 T-Bird, the trans is probably already slipping, but I think you said it was the V6.