Madness on the M3 prices but I know where there is a Hartge 2.7 lying for cheap which is every bit as good as an E30 but a fraction of the price. The one to go for is the Johnny Cecotto special edition.
Johnny C was the same as an Evo 11 I believe....Althought it's the Sport Evo ones with the bigger engine that commands the biggest premium the Evo 11 is regarded as the best of the butch to the ones in the know.