calmom makes a good point.
Unfortunately, this is not the only area in life where the deck is stacked against those with limited income. Given, however, the widespread suspicion that some courses that are labeled APs are either not really up to snuff or sometimes downright bogus, more and more colleges are clamoring for validation. Here's is a thread started by Tokenadult:
Harvard's Fitzsimmons on transcripts: "what you see is often not what you get"
Doubleplay: Some schools just do not offer APs; some that do waive the fees for low SES students. I know ours does.