I would say that 1/4 of retail would be great for your sale. Measure your yardage beforehand, and put little stickers with the size on each piece.
If you advertise well in advance of the sale (Craig's list), the quilters will go and you may have some who come prepared with their own boxes and tote bags. If you don't advertise to quilters specifically, then you won't have the foot traffic, and you will have more likelihood of hagglers who want to give you .50 for a six-yard piece.
Some will say sell it here, but it sounds as if you don't have time to either get the requisite number of posts per the guidelines, photograph and upload your batch of (no more than) 15 items at a time, or deal with emails and trips to the post office when you are needing to get out of the house fast.
Good luck with your upcoming move! It can be stressful.