Yes very true the UUC System U is pretty pricey,but like the others say forget the m3 exhaust not much hp gain in that,youll eventually want that aftermarket.
has lots of misc. addons if u dont want to spend all that hard earned cash on just 1 item. Oh yea check out the stromung exhaust videos, that one sounds pretty good but maybe find it cheaper elsewhere.
best of luck on your decision