The german stuff its cheap because it already has issues or its soon to bite you on the backend after the sale.
If you have any semblance of a "budget", please don't buy old ish/ high mileage german, especially obscure stuff... unless its a backup car. Its a cool ride till its finicky and/or always broken and that gets old reaaaalllly fast.
Also... A4, 3 series all the lower rung stuff is pretty meh to drive, not worth the hassle,...just go Acura, Lexus, SI, or a focus/fiesta ST or something. Even a nice Accord sedan/coupe with a 6 cylinder will really hustle and be around a long long time.