Guild Wars 2

If you speed it up when it’s almost done, do you have to pay the full speed-up price? Or is it based on how much is remaining?

When it is under 25% remaining hover your mouse over the speed up button, you will see it decrease in price as the seconds tick by.

So yes, it does adjust it based on how far you have to go.

From what I seen I believe it is cheaper if it is almost done. To be sure though maybe some others could confirm.