Most people collect something: hats, music, movie star items, animals, autographs, sports memorabilia. There are some eccentric and strange collections, too. Here are some items on Ebay that you could add to that collection, not found in any store.
Carafe and glasses for the alligator / alcohol lover
Connoisseur of fine drink? This item is for you. Collect alligators (specifically, dead baby alligator heads)? Then this item is worth the $199.99 listed price. A crafted swamp limb holds shot glasses and baby gator heads affixed to the sides. Another baby gator head acts as a stopper.
Antique Set of Teeth
These are porcelain teeth mounted onto a form. The seller estimates they are from the 1910's-1930's. "Samples of moulds a dentist could purchase back in the day." Seller notes, "Missing a few teeth. I have not cleaned these. Will leave that up to the buyer.”
Photos of roadkill
This seller, among antique pictures of interest, has several photographs of dead animals to sell for $15.70 each. Photos are 8 x 10; images are offered as a digital file for $75 each. The animals include a fox, several rats, and this kitten.
For the entrepreneur (who is not afraid of prison)
In case you were collecting information on how to do it, a book on how to manufacture meth, MDA, Ecstasy, "and other psychedelic amphetamines." Starting bid is $149.97 or you can make an offer (Already building selling techniques before you even crack the pages!). People who looked at this auction also looked at these other books: Baker's Famous Chocolate Recipes, Low Calorie Cookbook, and How to Restore Your Datsun Z-car.
Better have the space. 1928 Twin City 27-44, one of 839 made. This tractor still runs and comes with new fenders and hood as well as all the original steel lugs and wheel rings. The seller has a pasture of rare tractors up for auction.