Al,
if you are looking for investment grade coupes, you will need to make a few important decisions. are you looking for original / matching numbers examples? if so, that tends to be a rare coupe. coupe owners have over the years had a tendency to upgrade and rebuild their coupe the way that they feel BMW should have built them. mods such as a 3.5L engine, 5 speed, etc.
the best investment grade coupe is the CSL, especially the BAT 2 or the original carbed CSL ... followed by the BAT 1 or standard CSL. in all cases the non-citypack versions are probably the best bet. you need to look at the e9 registry and learn what the VIN differences tell you.
http://www.e9-driven.com/E9_Vins.asp
The downside of this discussion - the world already knows this and the prices are way up there already. price range - 100k to 250k
the next category is the most complete and most original coupe - with no rust ... or the fully restored coupe (with documented restoration). as you have probably read - our coupes have high risk of developing terminal cancer. alternatively, you can find a non-restored coupe in structurally solid shape and have somebody like coupeking, la jolla independent, the werk shop or Mario at VSR really go thru the car. price range - 75 to 90k+ all in.
a really nice coupe that has been well maintained - 45k to 65k
a decent / solid driver coupe - 30k to 45k
it can take a long time to find the right coupe. best advice - regardless of the price range, have somebody thoroughly review the coupe you think you want to buy ... if you don't get somebody like one of the restorers i mentioned, there are some very good people in your area on this forum. There are some high price companies that deal in coupes - like Hunting Ridge Motors, and a few others. there are also some scary people in California on ebay and other websites like CSi.
good luck - start reading and don't (necessarily) buy the first coupe you see. check out
http://www.e9coupe.com/buyers_guide/index.htm
for info on rust prone areas
