KTO1The specific artwork on these playmats are not available at those prices. The product you linked are mass produced by UltraPro at the release of a new set. They typically choose 3-5 images to make a TON of and offer them wholesale with a $19.99 MSRP.
These are still produced through UltraPro, as they have the exclusive license to print Magic art on Playmat, but through their artist program, which is a much smaller and exclusive print run, typically 100-500 instead of thousands.
Also, as these are produced through OMA, the artists receive a portion of the proceeds, which they do not with the wider release products.