Should I be concerned about scams or modified/counterfeit U.S. Mint sets on eBay? The seller has 88,000+ positive ratings but it sounds too good to be true for $165. How can these sets be sold for less than what the U.S. Mint charges? Here's the 1999-2008 U.S. Mint Proof Sets I am looking at: http://www.ebay.com/itm/20064584081...X:IT&_trksid=p3984.m1423.l2649#ht_1892wt_1002 Thanks in advance for your help.