For anyone curious like me, here they are: http://www.ebay.com/sch/tbhs575/m.html?_nkw=&_armrs=1&_ipg=&...

They're going for between $50 and $500 (most seem to be around $50 right now).

They're all in pretty bad shape. :)

Thanks for the link as the linked article is paywalled.

The 500$ cartridges are the ET carts. All the other ones are about 50$

I think the ET carts are the most expensive since that's why they started to dig in the first place.