Earthbound Beginnings English NES prototype on eBay right now at: http://www.ebay.com/itm/RARE-NES-Nintendo-Earthbound-PROTOTYPE-HOLY-GRAIL-for-Collectors-/142440060617
About one hour to go and currently at $4,550USD ($5752.79CAD). The seller bought it about a month ago at a YARD SALE for $5USD ($6.32CAD).
ITT you post tfw you will NEVER find anything good at a yard sale.