As much as it's everyones right to charge as they please, I never really understand people trying to be commercial about their photography and being cheap, but that's coming from a business background and seeing at a glance that the figures would never stack up to make a decent living from, let alone justify the time spent.
Personally, as a hobbyist who sells occasionally & a few contra deals in place I only have 2 prices. Free, or full fare. Never cheap.
*Free to family, friends & members of couple of sporting clubs I'm part of ...or others if I feel like it & I know it's appreciated.
*Full fare to anyone else or for commercial use - If someones making a dollar from my work then I need my cut as well.
Just being cheap to get odd jobs doesn't make much sense, either for your personal self esteem or from a commercial standpoint.