I do think it is important to factor in to the cost of your quilting what you would spend if you were engaged in another hobby or activity to fill that time space. It's not likely you would sit around and do nothing.
And factor in the amount of time, gas and materials you would put into decorating the room you are doing or the gift you are giving. Outfitting a bedroom in nicely appointed linens is not inexpensive these days!
And of course, the love and care, is beyond value!
Lisa