I was looking to put a 10w7 in the spare wheel and then the amps sunk into an elevated floor (similar to what someone else has done here w/ an A/D/S sub and amps). They quoted me roughly $500 a day for 2-3 days in labor only. Of course that's expecting them to work on the install ALL day.
Depends if the setup requires fiberglass / acrylic work or not. Basic box building shouldn't take that long. I'd say this setup was at least a grand in labor?