I have noticed an interesting pattern on the Ebay prices of these units. A week after a scenario is posted by AH, the prices of the minis in that scenario goes up. This happened with the KV-1, Panzer III, T-34/76, mosin-nagant. Looks like a lot of people are playing this game only with the official scenarios. I have finally managed to get my collection to the point where I have all the units mentioned in the scenarios and nothing more. I just traded away every unit that are not yet part of any scenario. Downside is if new scenarios come out with units I gave away I will have to buy them again.
I hadn't noticed the eBay effect of the official scenarios - interesting indeed.
Maybe try playing with the scenarios I've posted here (Under the Noel Trees, Sahara, and Wintergewitter)? These are ASL scenarios I've converted. I have the minis to play the first two, but not the last one (yet) - those Russian minis are so freaking hard to get, either from eBay or out of a booster.
Anyway, I'm planning to convert more ASL scenarios (I have several of the old modules and a stack of issues of the General to pick from).
If you play any of mine I'd be happy to hear your feedback!