That's pretty odd, but I can't say I know the answer to your question. I recently got mine (sealed in box) for $305 (thanks, eBay), and they are as advertised. That brings up an interesting point, though: The E500s always came with the PTH, I believe. As such, if you buy the SE530PTH, there seems to be a chance of you getting the E500. However, with the introduction of the SE530, Shure made a PTH and non-PTH version available. I went with the non-PTH one, and got exactly what was advertised-these were made in December 2007. Dunno if that's just a coincidence, but it might mean something.