Here are a couple examples:
These make great gifts and display very well for collectors. I accept BTC as payment, and would like to give a special price to anyone paying with Bitcoins. All orders will receive a 10% discount, and any order totaling over 1 BTC will receive free shipping.
My site can be viewed here:
http://www.cubicdissection.com/test/catalog/index.php
Some items are sold out, but there are still plenty of very difficult and tricky puzzles to be had.
Thanks and happy puzzling!
Eric
P.S. Be sure to check out the riddle thread where I have donated a puzzle as part of the prize:
https://bitcointalksearch.org/topic/over-riddles-second-edition-solve-them-and-harvest-the-loot-278129