any sales i have made have been with software that has a fixed price but usually when its on sale or in a bundle.Sales and bundles you can make, do have a really good impact on your page views. i would recommend it. It is a good way to keep a game fresh over time with new eyes. just have the occasional sale or make a bundle.
i havent tried much with pay what you want, most of my creations are pretty short and sweet and not sure if it would work for me.
I havent been here for longer than a year yet so im no expert, but its been great. dont be afraid to expriement with pricing. you can always change it as you go. what might be good for someone else may not suit you.
good luck :)