BSDCertification.org has the results of their “Test Delivery Survey” available as a PDF.  It “summarizes the results from a recent survey of potential testing candidates to determine their geographic locations, the price they are willing to pay to take an examination, and their thoughts on various methods for delivering IT certification exams.”

It’s mind-bogglingly complete like many of their reports, though I question the idea of surveying to see what price people will want – the only price anyone can agree on is ‘free’; nobody volunteers to pay more money, no matter how realistic the price.