I was exactly where you were and it didn't work for me. In my opinion the only way to build something substantial enough that is worth selling is to quit your job. If you put your whole mind to something you can accomplish exponentially more than being scattered about. I think a more realistic approach is to put all of your effort into saving money via a job, and then all of your effort into your own business. Jack of all trades, master of none and all that. Again that's my opinion YMMV. Whatever you are doing make sure you are enjoying it otherwise what's the point?