Do you know the name M Sipher? It's an encryption code used by the Predacons, and it's also an awesome Trans-Fan, Greg Sepelak. He's written a number of very well received Transformers stories, including this year's Animated BotCon precursor Moving Violations. Moving Violations is available for free online, so check it out if you haven't already.
Anyway, he's selling off large swaths of his collection. Check it out. Right now there are some great pieces, including a nice Thunderwing, Targetmasters Cyclonus, Scourge, Hot Rod, Kup, and Blurr, and more. Expand your collection while supporting Transformers creators! Maybe he'll throw in an autograph if you ask nicely.