I had this same problem, I think we all do when we first start out. When it was just me I could "afford" to go reset a GFI and sometimes not charge or charge very little, but now that I have employees I have to charge the same rate no matter how simple the job is. When I look back on it, I left way too much money on the table. Most of my customers seemed way too happy with my prices and I can now see why, the only good thing is that it gave me a good reputation in the community and the phone rings without advertising. So Maybe I'll make up that lost money in the long run.
