To resurrect a thread I'll add some 'costs' that maintenanceguy didn't mention but alluded to:
- the firsthand cost on your mental and physical condition when there's too much month left at the end of the money,
- the secondary cost on you when your adoring and supportive spouse accepts the predicament as a shared burden to be overcome when there's not much, if any, paycheck after your monthly obligations are met,
- the 7-day a week schedule you keep just to ensure your business runs as smoothly as possible and you're not behind schedule when you arrive (earlier than anyone else) on Monday morning,
- the dental appointments you or your family schedule every 5 to 10 years with the dental school because they're free or really, really inexpensive,
- the haircuts you allow your significant other to give even though they aren't the best and you say "thanks" and put on your hat,
- the six-pack of beer or soda you feel guilty over because it's truly almost a luxury...
- and so on...

My dad owned his own business (non-electric) and for years, as did my brother-in-law and I know it takes a lot to make them successful - but charging appropriately is a good place to start.