I don't do this full time. My full-time (8-5, M-F) job is a production specialist at Bitwise Industries. I have two daughters, and an apartment that I'm thankful for, but add up all the cleaning, cooking, and commuting in addition to my full-time job and there's very little time I have to spend as a family.
Every minute spent designing or editing pictures is a minute I'll never get to spend with my daughters. That's why, in essence, my time is money. I simply cannot do anything for free. I also cannot do much "rush" work. My turn-around times are a little longer than average, but I try to keep that in mind with my pricing. I also hope the quality of my work helps to ease any time concerns.
One day I might do this full-time, but until then please don't hesitate to contact me to see if I can help you with your next project. I'm also up for bartering.