http://www.ksl.com/auto/listing/1494655?ad_cid=2
I can get it for $2,500. People are telling me to snatch it up because its a great deal for a 325is. I am planning to use it as a daily that will occasionally see HPDE/Autocross/Rallycross time. It looks like it has minor rust, but all cars here do to an extent. Unless the rust is TERRIBLE, I will probably buy it. Looks super clean.
So, any pre-purchase things I should check? Common problems with these cars? Trouble areas? I do like how the guy listed it as a "V6" instead of an I6. Any advice before I jump on this tomorrow is much appreciated!
The hood gap on the front left. Could simply be a mis-adjusted hood, or evidence of a slight accident. Either way, check it out.
Other than that, read the buyers guides that you can find with a search. Much more comprehensive than what I'm willing to type out ;)
Looks pretty good in the pics..........seems to have all the desirable stuff. Not sure how he could get the motor wrong in "his little BMW" so that's a little suspicious. Covers on the seats may hide splits/tearing. Price is good. Check for rust in the usual spots, trunk, floor boards, rockers. If you can get underneath it that would be a big plus. Check Carfax. Good luck with your decision and/or purchase.
Check floors, trunk, rockers and jack points for rust. Plan on doing a timing belt and water pump IMMEDIATELY upon purchase; don't trust what the seller says if he claims he just did it.
Lower suspension, replace bushings, add sway bars, drive it like you stole it. 
There is a nearly 100% chance that the odometer isn't working. (they all break) Perhaps you can use this as a way to whittle down the asking price.
There is also a very good chance the "Brake Light" warning will be on, but the brakes are fine. Since the seller doesn't know his car very well (calling it a V6) you may be able to use this too as a way to get a better deal.
Great cars---- if you get a good one!
Check the rear subframe mounting points and rear shock towers for rust. These are both expensive fixes.
$2500 seems a little high unless it's because E30s are getting a little scarce. Also, the front control arm bushings are integrated with the arms, so if they're worn out, you have to replace the control arm.