Have you calculated the costs involved in your business? If not, that is the first place to start. You need to generate sufficient income to cover your expenses and provide a profit which you deem reasonable. Costs aren't necessarily limited to equipment but, depending on many other issues, might include business licenses, rent, income taxes, insurance, etc. Many small businesses fail because the business owner fails to anticipate the expense involved. Once you determine the cost of doing business you can then make an educated guess as to whether the income you need to produce a profit will be something your prospective customers can afford and which will produce a sufficient customer base in order to produce enough revenue to make the business successful. If all you are interested in is an hourly rate based on time expended then figure out what your time is worth and charge accordingly. You may or may not have sufficient customers to produce the rate of return you want and you may have additional expenses which you didn't anticipate such as claims by customers for defective work or "damaging" their knife with no insurance coverage, a business license expense when a neighbor complains to city hall, etc.