http://www.onlineindustrialsupply.com/abrasive-sheets.html
Every grit you could possibly want. Is it Norton or Klingspor, nope. The prices went up a bit but 50 sheets for that price, I don't really care.
I'm not an expert finisher and don't do much other than spot repairs. I have finer grit auto body paper in better quality for that.
For your everyday shop use, this stuff works great.
I have to admit, must be that my Father is Scottish. When I load up a piece, I set it aside. When I get a handful, I take it upstairs and put it in the sink. I wet it and have a scrub brush. I scrub the paper and find some secondary use for it in the shop. Some of it can't be salvaged and some can. It only takes a few extra minutes to scrub it.
I've used the 2500 and 3000 on water based poly and the finish comes out pretty decent.
Maybe you guys get it cheaper in the US but I don't like paying a buck a sheet for a 4 pack up here. I'd go broke buying paper.
KJ is probably gonna have a laugh at me now being an El Cheapo paper scrubber.