The steps or bid amounts vary on the price range of the product. I cant really call this a bug as this is the way the developer has coded it to work. Now things always change and I suggest you place a suggestion in the suggestion forum for such a thing.
TCMDEB this is how it is suppose to work and how ebay does work as well. Thats why you place a maxbid. When someone bids and your bid is increased to automatically outbid the person and remain on top of the bid until such a time your maxbid has been surpassed.