You could take a look at Priceline.com.
They don't have the bidding anymore but they still have "Express Deals". I wasn't sure of your return, so assumed you'd stay about a week. I could see $260, although there will be some fees added on.
But carefully check all the conditions - time of day, stop or non-stop, etc. I haven't used this option personally.
You won't have a choice of airline or time of day.