YACT: How much labor to replace a Bose sound system?

[RgrPark]

I have a 91 300zx 2+2 with Bose speakers... I already swtiched out the headunit but 3 out of 4 speakers are bad. I'm not a sound guru and it seems pretty complicated to replace the front door speaker myself, so i'm wondering how much car audio places ususally charge to install speakers...thanx