I'd say somewhere between a 3.5 and a 4.
Almost every page of my comic represents the best I can do at the time.
If 5 means "you could go pro..." Well, i probably could if I learned digital coloring and really applied myself.. But I don't. I have no interest in doing commission work or drawing other peoples' ideas, honestly, so unless I was doing my own comics full-time, I probably couldn't make it as a professional artist.
Plus, my personal idea of a 5 would be someone like Katsuhiro Otomo, Geof Darrow, or Andy Brase. (Google them. They're awesome.)