I have a quarter sheet (Porter Cable) sander. I'm about to start the sanding process. I'd love to get a variable speed random orbital sander, but it's not in the cards right now. I either use this sander, or I do it by hand.

My question is: Does anyone have any tips of where to get cheap good sandpaper, and what kind is best for sanding epoxy? I know I'll go through a lot of sand paper, but I think I'll feel better about it if I buy it in bulk up front for a good price. Home Depot feels expensive. Is there anyplace cheaper out there? Mail order or web based is fine with me.

Thanks for any help with this.

-Dan