Posted By:
WesleyI agree with tbob in that those who own the E103s are probably just squirreling them away. A few years ago, there was a collector/auctioneer/forum member who seemed to have quite a large hoard of E103s.
As far as E90-1 cards, there are two complete sets on the SGC registry. Sotheby recently auctioned off a complete set as well. I know of a few other collectors with near sets and recall seeing several partial sets in Mastro.