I am the newest of new slot card collectors, but I am very active in other collectibles. Some people are much more agressive than others in their drive to have certain items. That's true in all endevores. A real guilty partner in this is Ebay. They have an obligation to ensure a level field to bid. There is NO way that a seller should be able to change the auction to a "Buy it now" once there has been a bid.
Yes, there are other ways around this, but Ebay owns some fault in this. In MHO