You can't really put a time limit on it. It may take certain animals more time to eat 3 meals than others. The usual process is after they shed then you offer their fist meal. They may not eat then. So 3 meals, however long it takes, is the minimum I would wait for a newly hatched ball.

Second. You put a deposit on a snake that has t hatched yet? What if the odds gods aren't with ya. Did you make sure the deposit is refundable? I hatched a spider x normal clutch last year, 5 eggs all dudes. I would be wary of any deal which involves snakes that haven't hatched, let alone ate yet.