I was in the same situation 13 years ago with choosing between an e30 325is and an e30 M3.
at the time, a nice e30 in the prairies cost me 7200. Kinda steep, but it checked out well.
A similarly equipped e30 M3 was going for about 12-15 g's. At most, 20g/s
I thought it over and since I wasn't going to mod it like crazy, decided on the 325is since it was easier to daily (even though I just wanted something nice in the summers).
Today my nice e30 325is is worth about....10ish....at best
an equivalent e30 m3 is worth about...40-50ish...at least!
do I feel like an idiot?
you bet I do!