It really depends a lot on how well you know the person (No, you don't charge less to friends, a good friend knows that your time is valuable and will be happy to pay what you are worth), how complicated, what size, and how much time it takes you to make it. Charge actual price for the materials, even tax if you paid it (If you have a business license you don't pay taxes)and a reasonable amount for your time. If you charge too much the customer may not come back (yes, sometimes this is good) but you need to value yourself first. You can either charge by the hour, regardless if you are piecing or quilting, or charge less for the piecing time and more for the quilting time. some people charge more for complicated quilting designs and less for simple ones.
I always prefer to make a quilt and then sell it for the price I would be willing to pay if I went to a place and saw it. I have done a few commissioned and may never do it again, unless is a remake of an already made by me but in another color or size.