It would be much more satisfying if you could make an automated option where you can choose between the option of you "maximum" bid,
with an increment (i.e. $0.01) of the highest recent bid (perhaps 5-15 minutes from auction closing time) AND a "maximum" bid. That way, if the highest recent bid is higher than your maximum bid, nothing will happen. On the other hand, if the last highest bid was a great deal cheaper than your "maximum" bid, this would save a lot of unnecessary spending.
Of course, just making this an option would be best, seeing as there are different situations for different cases.