I have been using the 3M 9” X 11” sheets of sandpaper buying from the BORG. I cut them to the size I like. It comes in 4 sheet packs. It was $4.99 for a pack, but yesterday I went to buy some and the price has gone up to $6.19 for a pack. At that price I am looking for a better option buying on line. I use the Klingspor foam for above 400 grit and that is fine. Are there less expensive options for quality sandpaper?