[GLE]

How much did it all cost?

Looking to get it done at a shop, I want to replace the head unit, all the speakers, add a sub and ofc the amp

 

[GLE]

2006 Mazda 3 Sedan btw

 

[Studum]

It depends entirely on the equipment you choose, how you want it installed, etc. The sky is the limit. If having it installed you're best off visiting a few shops to consult on equipment - feel them out to see if they want to work with you and if you feel you can trust them. Pick your equipment then get a quote on materials and labor for install.