Ugh, that's so frustrating! I'm really sorry, and I know that tons of users have had similar things happen.

It's really difficult for us to do something like this, because there are circumstances where item prices change rapidly. When we release new items, when an item gets a re-release in another venue, when a user with 5000000 of something opens up their vault and sells it, etc. It's really hard to tell (from our limited data) when a price choice is on purpose.