Speaking from 30 years retail experience...sit your butt down and stay! You are never going to make money in retail period. It's been my experience that everything promised by way of bonus is tied into things beyond your control. If someone will give you ALOT more money via salary that's one thing. Or a bonus related directly to something you can control that's something else again. But you can't control the amount of advertising they do, the product mix, the training of associates etc and those ALL effect sales.
Jumping into a pool when you don't know how many sharks there may be is unwise. Stay put and count your blessings. You may think about letting your supervisor know that the job is a financial hardship and see if there's any room for a little more money to make it worth staying.
Claudia