That is the million dollar question for many. Even when I was contracting and building kitchen cabinets that was always the plague. You want to have it value priced but not be too inexpensive either. As a hobbits it is easiest just to make sure your costs are covered and add a wee bit for time. As you get better at the projects at hand you will see what others are charging and get faster while putting out a better product. If you were actually doing it as a business there are a ton of other costs to track as well. Then when you break out your cost and labour you need to include contributions to general overhead so that insurance and admin costs as well as amortization of fixed assists and sometimes interest can all be factored in too. Depending on how far you want to go and what you are looking at. Do you want to have a legit business or just fly under the radar. It is a deep subject that we could chat over many cups of coffee about. I am sure that there are other guys here with more experience and education than I, hopefully a few of them will chip in here too.