I've always been a strong believer in the "that OS that shall not be named" Bounty System.
It gives users a chance to donate, and developers something to work towards! Plus, the more the bounty, the more those said developers know how much interest there is in a particular area and have confidence to develop a program that can be upgraded as time goes on, maybe with updates for a small fee! Sort of like an ongoing income.
That's my opinion anyway, whether liked or not
Rude!