I've had this proof set for years, and I just noticed that the date is doubled. Wonder what it's worth???
I wish you had a microscope like this also. Then I wouldn't have to post online... I could simply send the coin to you and you could look at it. http://www.accu-scope.net/accu-scope-3002SPH-microscope.html
It does look like a real doubled die to me, and my guess might be a $150 but I have no certain idea about the price. Ruben