I never thought I would see a 1976 Proof Set sell for more than $10, much less the $550+ for the set offered below: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3913777630 I think this stuff could become the next "coin bubble"
And after a few more years, there may be 5 times as many above. And you know the pops will not be inflated by "crack-outs".
This stuff was the last "coin bubble" - not the next to be. Prices for ultra-high grade moderns have been dropping rather steadily for the past 18 months. And they show no sign of slowing down anytime soon.