I guess I will defend VMK on this one - since I've complained about them on other topics.
Yes, I think they knew that the answers would get out and that several people would solve it, share solutions and help their friends and whatnot by either getting suits to give them or helping them solve the puzzles themselves. And maybe they thought there was nothing wrong with that. Afterall, sharing and helping others is not out of line with Disney's image.
But, at the same time, there was certainly a possibility for these diver suits (like all those Hidden Mickey photos and, for that matter, the Kellogg's magic pins) to fill up VMK and, fates forbid, slow down the game. So maybe, just maybe, after giving us a week or so to share them with friends or cash them in at a "special" price, they have changed them to what will be the permanent method of delivery and sell-back price. Think of last week as a special introductory offer.
As for the price of the helmet ... well, economic decisions are a part of everything. You can get a helmet ... or you can get four skeleton chairs. You decide. It's not real money, so I don't really care too much what VMK charges, and ultimately we all have to decide what is "worth it." (Do I really want to Ned for 3 hours for THAT?)
That covers the diver suit and helmet. I can't explain the price jumps at the Emporium. VMK is on their own on that one!