Transformers Titanium Series

So here it is, the first thing to be added to my list. Well, first four things, technically. So what exactly are they? First off, sorry, but the only decent picture I could find was the one I already had. What you see in front of you is a tiny statue of a Transformer, in this case, Unicron, the planet-munching chaos god from the first Transformers movie. It's something of a contradiction in terms, a Transformer toy that doesn't transform, but I think they're really cool, and I'd really love to add several of them to my collection. They come in two sizes, the three- and six-inches, the latter set being able to actually transform.

They are all really cool, and I would enjoy any of the set, but there are a few characters I want more than others:
-Bumblebee
-Starscream
-Megatron (the 6in 'War Within' version)
-The Autobot Starship Ark
I've already got Unicron, as well as the six inch Optimus, also from 'The War Within', but really, any of the others are pretty much fair game. And you can get most of them for under $10 at any toy store, so that's a plus, right? (I'm trying to keep price from being an issue, but since so many of the things I want are on the expensive side, I'mpatting myself on the back for starting out low.)