Now they are but the line's been done for a while. How hard or easy to find they were depended on how often you went out, what stores you hit, when you hit them, and also just how lucky (or unlucky) your region turned out to be.
For instance I know Rob's seen shitloads of them at his local shopping treks, but for me I didn't see so many. I really lucked out when I found a passel of them for $7 each at an area Wal-Mart once, but it was only like 7 or so, not a lot...
I saw them a few times at Toys R Us but in no huge quantity. At most I think I saw 4 at one TRU once.
Target I don't recall seeing any... I got most of mine at TRU, then a handful at WM, and the rest I've traded for online. I got one at KB too in an act of desperation for more.
For my area they were NOT common. Nor was the Evolutions line. These items were not shipped heavily up here at all. Even the local scalpers don't have these things in abundance it seems.