Although I own 500 of them, I know less than anyone. $20? I'd think that would be about right if you can buy one alone. I got mine in a monster box, unopened from the mint to a dealer to me. And I have no intention of opening it up. Will leave it with my estate when I depart. Three years from now.
EZ2, check out the latest offer from APMEX: SPECIAL PRICE! 2015 1 oz Silver American Eagle BU (Lot, Roll, Tube of 20) $385.00 with free shipping = $19.25 each. (via Ebay)