Free or Inexpensive Volunteer Scheduling Solution?

Just curious if anyone out there has used any free/inexpensive volunteer scheduling solutions on the web like Doodle or SignUp? Or is there any relatively inexpensive scheduling solutions that anyone would recommend? We are in process of evaluating changing ChMs and need something to use temporarily until we can make the decision and change. Thoughts? Comments?

I used Doodle to get availability, then ask people each week manually, if their plans changed, I go to the next person who said they are available at that date.

Crew (crewapp.com) is a good one. I know there are several companies that use it, but their main users are on their free tier. WhenToHelp.com also often offers free to non-profits.