"non-woven filter media" sure seems to bring up a lot of listings for foam instead of non-woven media.
Not sure if this is the right thing, but price seems a bit better than $300.
Picture is a bit weak for judging the material,etc.
I didn't see a thickness mentioned, but other stuff in that ebay group seems to be labeled as an inch thick. Maybe this will get ya closer to what you're hunting?
Photos show the item you will be receiving.
www.ebay.com
P.S. you might find something in a janitorial supply? I'd look for the non-abrasive buffing pads and see if something would suffice.