You play, you should get paid. End of story.
For those volunteering for free...well, best of luck to ya. You'll probably NEVER get paid. For those in the paid band helping rehearse the NON-paid volunteers....you should be ashamed. Degrading the profession that is worthy of much more than just a working wage..... I'd quit and work in a local top 40 band before going to that level.
But not that surprising. If you value your art...don't give it away.