You've definitely blazed an impressive intial trail into the mini-bust line, Rob. I got into this line in a big way back in 2004 with the Biker Scout. I had lucked out the year before when I got the blue Clone Trooper mini-bust at Wizard World Chicago. Talk about LUCK! If I knew then what I know about the mini-bust line now, I would have been doing backflips the whole way home from Chicago.
Backtracking is definitely a little tough. I guess I've had it a bit easier since I got every mini-bust release since the summer of 2004 at retail price or lower with the exception of the Blackhole Stormtrooper. But backtracking on pieces like the AOTC Yoda, Jango Fett, AOTC Clone Commander and Boba Fett definitely cost me. I still have two backtrack pieces left on my own list: the 1st edition Darth Vader (which I've got a great lead on) and the red AOTC Clone Trooper. That one is going to take some considerable time/effort/cash. As for your own list of HTF mini-busts? Save the searches for those on eBay and get email notifications on them. Track them and decide for yourself which ones are worth bidding on and which aren't.
The good thing you've got going for you is that with this years's line somewhat well laid out, you can plan for some of the exclusives if you're really hot to get them. The Clone Commanders might prove a bit of a challenge, but they shouldn't be priced to crazily.