This post follows up a question I raised in another thread here at the workshop.
I went and looked through all 800 or so US based auctions for sandpaper on ebay. The going rate for you-pick-the-grit wet/dry seems to be around $0.75 to $1.00 per sheet of 9x11 shipped with grits ranging from 80 to 2500 grit.
Here's the best deal I found: 25 sheets, u-pick for $18.50 shipped
This equates to $0.74/sheet of wet/dry sandpaper.
25 Sheets WET - DRY 9 x 11 Sandpaper You Pick the Grits - eBay (item 160332411549 end time May-31-09 16:46:30 PDT)
They have 80, 100, 120, 150, 180, 220, 360, 400, 500, 600, 800, 1000, 1200, 1500, 2000, 2500 grits available.
Bruno recommends progressing from 220, 400, 600, 800, 1000, 1200 to 2000 on the wiki.
Any input in terms of quality or type of sandpaper from restorationmeisters welcome.
Conflicts of interest: I am in no way affiliated with the seller.