There was an article recently that talked about the problem of people asking what programming projects they should work on, and how that was really the wrong question to ask in the first place. I wish I could find it again, as there are some parallels to these kids of questions.
The answer to your question though is work hard and ignore your kids. Get a promotion by skilling up then move to a high paid job.
Or start a online company, sell something but make the site also make people want to come back, as before work your but off, know your product inside out, stopping wasting time on the little things.
skilling up and being promoted has already happened, although there is always room for improvement.
i thought it was obvious, so i didn't mentioned it, but i am a professional programmer. so doing something online is, for me, the obvious thing.
i was thinking in the line of a dating site or some social news site in niches that weren't explored yet, but thought that maybe the HN community might come with something more original.
doing the freelance (10 hrs a week X $50 per hour) is for example something i didn't thought of because i am oriented toward building a product or service. i am not sure i can add the extra work for so long (4 years) and i am also skeptical about reaching customers. but it is surely something i should consider.