I live in middle Tennessee and currently charge 125 for the initial diagnostic labor which includes 1 hour. total with tax it comes around 141.30 with shop supplies. My shop rate is 125/hr. I find i have a good set of base customers so far but have been extremely slow and a lot of the time struggle to acquire new customers. Many guys in my area charge so little for vehicle repair its actually ridiculous. (35 min east of Nashville) Does every customer get mandatory 1 hour of diagnostic no matter what? what is your maximum travel distance? No customer supplied parts? I use all data, ARI software for invoicing, QuickBooks for taxes and mark my parts up accordingly and am very profitable if I can get the customers business. Where I struggle is finding those high-quality clients who won't waste time and try making you feel bad for charging the way I have to.