I think I've talked to you before akahenry lol
I've had M7 catback on a brz for couple of months now and it's great.
Expensive? yes. Worth it? ABSOLUTELY.
I could only wish I could sit you in my car and show you how it sounds in real-person.
And where did you come up with 1.5k? Even with installation m7 catback is not gonna cost you that much..