....if someone were looking for, say, 500 images of one particular subject, say, body piercings....where would a good place something like that?
you could try in the buy and sell section if you are asking where to post to find someone selling bulk images.
for getting large amounts of bulk dirt cheap stock images, I visit places like Walmart. Sometimes their bargain bin has piles and piles of stock images CDs and Cliparts CDs for only a few bucks. See if you get lucky! Hope that helps!