E30 Zone

have always wanted one of these,have a budget of around 8.5k.
have heard these can be a nightmare to maintain but have a mate who's a bmw specialist,looking at 840ci sports in particular year 1998/1999.
any advice???

How good a mate?

he's a good friends cousin but have known him for a few years now,if he has time ill get him to inspect the turd of my choice.here is my shortlist of potential turds:
1)e30 325i sport or tech2 motorsport cab(manual)
2)merc 190e 2.3 16 cosworth
3)e31 840 ci sport
4)r129 merc sl
5)yet another e36 m3