âAdvertisement promoting the Imperial Academy. An Imperial Academy was a military training program run by the Galactic Empire, and primarily focused on training both the enlisted and officer corps of the Imperial Military.
People have created accounts and bid on their own stuff to try to raise the price. If caught, they are deleted from the system by E-bay. As many people wait until the last few minutes to make a bid, it is probably the surest way to win something.
If the original highest bidder also had a maximum bid of $20, once you bid above $12 the price will jump straight to $20 as eBay automatically bids for both you and the other bidder. Therefore the highest bid you see on the item depends on both your maximum bid and and maximum bids of other users.