Hi Eric

Lapel pin badges are highly collectable on eBay.

This particular design is probably commanding such a high resale price because of it's rarity value.

If this seller is only selling one your designs as his own 'used' property, he is probably just an avid collector or a seller with a shrewd eye for buying and selling collectables.

However, if you think he may be selling these commercially in bulk and you own the copyright, have a look here:

http://pages.ebay.co.uk/vero/