How much does it cost to watch television? How much does it cost to take a nap? How much does it cost for you to spend go to a play?
These decisions have inherent opportunity costs. While you decide to do one activity you miss out on dong other activities. Before engaging in any activity you need to ask one questions, is this activity worth passing on the other activities? If the answer is yes proceed, if not you have to re-evaluate. This exercise takes disciple but it is well worth the effort.