It might help if you can e-mail the seller in the US (when buying of eBay) and ask them to either send the goods as a gift and/or mark the parcel value as no more than $50, that way you don't need to pay any import duty.
Bought my iPhone from the US off eBay and the seller marked the content value as £25 and I didn't pay any import tax on a £300 item (bought my iPhone when they first start hitting eBay in the US)
Also what works is if you have someone that is a student and have it sent to them, as they don't have to pay import duty either.
true but the mats the OP is looking at aren't from ebay US. You also then run the risk that if the item should go missing that your only insured for the $50 you asked the seller to put on