Looking for a Pay What you want plugin.

Hello.
I am currently in need of a special plugin to allow people to be able to pay for something I would be selling on my wordpress site. But the kind of plugin I am looking for seems to not have been made yet.

The plugin I would like is a plugin to allow the user to put in the amount he or she may like to pay for what I would be selling.

Kind of simular in a way to how Humble bundle sells games on there website.

http://www.humblebundle.com/

This plugin would need to be able to be added to a page. And maybe add a highest user contributor’s list. and a total payment information similar to how that humblebundle page works. (Currently there is no humble bundles being sold but you can see what I speak of on the site above.) If any one knows of a plugin already like this.

Or would be willing to make a plugin simular to this. Please let me know.

Thank you.
Night Hawk.