installers pricing, what to charge?

Ok guys question for the installers.

I worked as a installer back in my early 20's. Life led me to a career in aviation. I still enjoy car audio and am the all around geek i guess you would say lol. I started doing installs at home and at customers places as a way to make extra cash a few years ago. i advertise on craigslist and facebook and through word of mouth. I try to look at each job individually and price accordingly, all the while   trying to beat he prices of the high prices places around here ex. Best Buy.

Had a guy tell me today that i was too high on price to do a radio and four speakers on a 2003 Stratus sedan. He said someone else told him $70 total. That sounded pretty low to me. Am i wrong thinking that? my price was $125 total.

What kind of prices would you guys think someone working on the side not out of a shop should charge.

Thanks for the feedback