I started InkedPlaymats.com a month ago. I work full time as a purchasing manager, have 3 kids under the age of 5, and take online courses full time. I am way over my head and sleeping 4 hours a night, but I am making it work. I am getting a 4.0 and just after a month open my business is starting to boom. I get up early and make breakfast and get orders ready to ship. I spend my lunch break shipping items and answering emails. I come home from work and spend 2 hours having dinner and playing with the kids. I then spend the next few hours doing schoolwork and printing out mats. My wife supports this knowing I am in a growing period. School ends this week, so I am looking forward to that. Anyways, I think it can be done, but is not ideal. And your family has to support you 100% of you will be lost.
I should stop being an anal-retentive entrepreneur and just hire a graphic designer. Am considering commissioning custom art from an MTG artist (rk post maybe?)