Looks like they have fixed it on the Feature page.
Actually, there is a longstanding problem in App World caused by slow synchronization of various RIM servers. When a developer makes any change to an app (whether it be description, price or anything else) there is a period of time when some servers display the old information and others display the new. I am told that when you actually make a purchase, you will always be paying the correct (i.e. the most recent) price.
I made a purchase on one of the Gameloft games that went on sale awhile back, and the sale price was not reflecting on the final step of the checkout, however I didn't notice till I got my email confirmation and saw I was charged full price. I emailed RIM and they were quick to send me a refund of the difference.
But yes, it is a major bug and they need to fix it ASAP. I'm sure it's keeping their support team busy issuing refunds. And there are a lot of cranky people complaining about it on twitter.