Well, my opinion is that EP III seems to be a little different than EP I and II.
EPI and EP II seemd to see vintage prices jump a good bit, to later settle. For some reason, now with EP III prices are all over the board on everything both vintage and modern.
There are some vinatge pieces that seem to go for 3 times what they were months ago, yet, at the same time there are some absolute steals on some vintage items. Certain figs seemed to not have budged, vehicles and playsets don't seem to be going real high, oddball stuff can be found pretty easily and very affordable.
I can;t explain, maybe only that there's been just so much stuff produced over the last few years, and all the influx of the modern for EP III maybe has put a "lull" on vintage for a small time period?
I wouldn;t worry, I think it will be strong in the long run, but when I see a modern Clone Wars Anakin starfighter go on Ebay for over $90 (that had been sitting on shelves a year ago) and Unleashed figs for over $100 (that also had been peqwarming just 6 months ago) and vintage boxed vehicles go for $30 or less (that are almost 30 years old), to me thats just screwy, and I couldn't explain it in a million years.