730i E32 Bj ’87 Maintenance costs

Hallöle, am 18 years old (drive an Audi 80 B3) and would like to buy me a BMW 730i BJ 87 with 290 000km for the summer. The car has no rust and is still quite well there (should cost about 1000 Euro). Now I just want to know if one of you has had experience with such a vehicle and what the vehicle costs in the maintenance (taxes, insurance…). I thank you already in advance for numerous answers. madmax.krau 🙂