Have you tried downloading and using Rivatuner? This program has the option of setting fan speed at different levels according to the application you are running e,g, 2d apps low silent fan speed, low level 3d apps medium fan speed and games etc high fan speed.
My gt was always at full speed and noisy until I used Rivatuner, now it only gets loud during a game but obviously I do not hear it with the sound of the game! I would recommend you try it before spending on another cooler.