So it goes up by increments of ten right? Heres a hypothetical situation: Say it's at 23730 when you hit the button. Then you type in 2374089 (23740 is the number it gave you when you hit the button) even though you only have 35000 and hit enter. By then, multiple people have already bid and it's at 25830, and your bid goes to 25840, because it is the next number in the increment cycle of 10. They do this by time instead of letting us choose the amount because things would be much more expensive and people would complain.