What are you going to do, if you can't get it? What if someone is always bidding higher and outbidding you? That someone might not even be human.
A bid robot might be what you up against, a 'machine' that bids higher, immediately and every time when you or someone else has placed a bid. This happens and speeds up often in the very last seconds of an auction leaving lower bids behind.
To protect yourself against such hi-tech bid wars and to protect you from bidding over and above of what you initially were willing to pay, decide before placing your first bid how high you want to go.
In the last seconds of an auction, even during the very last second, things might happen so fast, that the domain you have set your mind on get snatched.
By placing the highest possible amount on the outset, your money is protected, because a bid can only go up so much each time as explained below.
At sedo a current domain auction price of $100.00 will increase by only $10.00 each time, when a higher bid is made. Once the domain is bid up to $500.00, the increase is $50.00 each time - and a domain auction having been bid up to $2.500.00 will increase by $100.00 increment, until the domain reaches $10.000.00.
That is, if you really want it.