You pretty much just answered your own question; scalpers just buy them up in ridiculously large amounts, and sell em off on ebay, leaving the "shelfwarmers" to sit there and rot.
Yes, scalpers suck.
Lol...I guess I spoke too soon. I went to my local Target today to kill some time...and what do I see? I got Ravage, Grimlock, Swindle, and Windcharger. They still have some left...but barely. I guess the scalpers got to them early.