The GDC price is regular retail, $25. But last I checked, they are saving them for their testing families. We got one when dd was tested, and then to make a long story short I needed another one for a close relative, and I had to beg and plead to get them to sell it to me - it was not easy. It can't hurt to try, so make the call, but I don't think the GDC is selling to just anyone - I assume they're trying to make their supply last as long as possible because it's out of print. I wonder what it would take for the publisher to print more. Once, on googling the title, I found some sort of book distributor who had it on their list for a bookstore to order from (at regular retail price), but it was impossible to know whether they really had it or not.
