This is a thorny issue it seems. Does the responsibility lie with the purchaser of the ticket to follow through diligently with booking policies and procedure and double check; or is the onus on the website to provide the appropriate charge in the first place?

The funny thing is that when a mistake fare is loaded in the system, no one in their right mind will do the previously suggested actions of calling the reservation line and verifying the price; because typically the explanation is, "the system said it was priced as this, and how would I know the difference?" But in this situation, that just isn't sufficient.

Or, take it to the other extreme, the system OVER-charges; how would the purchaser know that? Would it have been SOP to call the reservation line to confirm the price?