Should I keep looking for a job or be satisfied with what I have?

I have a supervisor position teaching high school kids how to paint. It pays $12/hr, and pays enough to save for an apartment. I still need to buy a new laptop though, and it's a seasonal job that ends in August. So, I went looking for another job to supplement what I have now that I can carry through the school year. I got a job offer working for Bebe, and they pay $8/hr plus 5% of individual sales. I heard though that some retail places offer more for starting positions. Should I keep looking for a better deal or take what I've got?