Getting items graded by AFA is not cheap, which has to be factored into peoples asking price. But IMO 'Buy it now' prices on eBay for AFA items are usually very over priced, mainly due to the sellers greed! However, (as already mentioned) for genuine auction listings it is us collectors that determine the price.
I personally don't aim to buy graded items. I have some in my collection, but due to shopping around I got them for less than I have seen ungraded examples sell for.
I would imagine that a lot of the over priced items sold are purchased by new collectors who have a large disposable income and don't know any better.
I have never understood U grading loose figures or the premium they attract! Surely an AFA 85 figure is in the same condition as an AFA U85?
Other threads have highlighted the floors in AFA e.g. inconsistant grading of moc's & grading loose figures with repro weapons!!
In time I'm sure the prices will settle down.