I signed up, but Open Tasks is empty right now. It might be interesting to report info about completed tasks---to give an idea of the prices and type of PRs being requested.

This is an interesting idea with several possibility of incentives: project owner, project users, or companies employers could sponsor these PRs.

Also could be useful for learning/tutoring---formulate a question you're stuck on as an Issue and let an expert show you the way with an educational PR.