It's definitely the price of the Dinan exhaust that makes it look out of whack. The pricing of the software is pretty much in line - I think Conforti runs about $250 for the SW and/or $350 for the Shark Injector. As Ghostrider states, the Conforti software isn't available yet for the E46 (anyone know more info?).
As for a company like Gruppe M, ECIS making SW recommendations, they probably won't make an outright recommendation - though your local performance tuner/dealer will probably have some input.
Hell, I think the knowledge base on here is probably plenty valuable to help you make a decision.
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