Raffle plugin

I require a Wordpress plug-in that allows for an online contest to be run. I should be able to set the starting and end times of the contest and users will be able to buy tickets during the duration. I'll be able to set the prices of these tickets and they will be used at the end of the contest duration to pick a winner. Depending upon how the coder wants to implement this plug-in the plug-in could either use its own method to implement a payment gateway, or it could interface with the WP e-Commerce plug-in allowing that to manage payment.