E-Bay bidding explanation please?

Ok so I put in a bid on an e-bay item. The starting bid was less than by maximum bid. So it automatically placed the price at the starting price. There has been one additional bid since that time. I would have guessed that bid would have been slightly higher than my maximum bid to give the other individual bidding the best deal. Instead the item took a huge jump in price and is now way above what my highest bid is? What is going on there? Any help of suggestions?