Yes, I also understand from the author's webpage that the print run is 2500. And Amazon does seem to be the only vendor, at least for now, as they do say "Exclusive" Limited Numbered Collector's Edition. Shame they're not signed but you can't have it all, huh? I'm keeping mine unopened for the future, but that means I don't know which number it is, which is presumably stated only inside the cover - can someone confirm this? Thanks.
The number is inked in on the title page. The title page says: "Exclusive edition for Amazon This edition of I Shall Wear Midnight Is limted to 2500 of which this is number ___/2500" The page also bears a drawing of a Nac Mac Feegle. I suppose this is the additional artwork.
I have to add that this edition is not really worth the money. Cheap paper, glue binding etc. For anyone who knows the quality of limited editions from the likes of Subterranean Press and others, this edition is really shoddy. Printed by Clays, the Dibblers of printing