The first couple of weeks, it was a total pain to get them all, and I also had a hard time getting the plush ones. The Jawa and Chewie in particular took me until week 4 to find.
I got Vader during week 5, which was great. I figured I'd still be looking on ebay for one had I not found it then.
I'm glad that I don't have to go to BK every Wednesday to get these anymore. Now I wish I'd have picked up all those Episode I toys and cup toppers, and I want to complete my 1997 Taco Bell set. I think I need R2, Boba Fett, and that Vader/Yoda cube thingy.