Lets clarify something right now. An E30 325i/is is a FAR better *street* car than an E30 M3. End of story, especially with the correct minor mods. The E30's S14 is a great track engine, but not great in the real world of traffic jams and around town driving. The E30 M3 beats itself to death on rough roads. And there is no way in hell an E30 M3 -stock- is doing 0-60 in 5.5, more like 7 seconds. An E36 M3, though poo-poo'd now as boring by many, is a very capable car and even an E36 325is/328is is easier to drive fast than the vaunted E30 M3. Having said that, an 88-91 M3 is a *BLAST* to drive, especially if you squint and pretend its the 1990 DTM series
And the other poster is correct, there is a $15k rule to all E30 M3's.
I had one, sold it for a Corrado VR6 which my sister totalled, now I have a modded E36 325is.