The licensed themes in particular seem to have taken a slight jump up in price. The 10 cents per piece rule of thumb is pretty much obsolete. Original themes are not immune, however. I've noticed a few sets here and there that, not long ago, would have been $9.99, but are quite a bit higher
...though, fortunately, it only happens now and then and isn't the case across all small price-point sets.
I'd say it's just the rising cost of production/distribution/etc. And the world economic situation can't be helping. It could also be that when LEGO renewed Lucasfilm licenses, they got a bit more pricey and it took this long to see the difference.