I agree with Ryan,

While I would be happy to pay $20 per hour, I wonder what is going to stop just anyone using that pricing scheme, their would be no one to stop a company using the cheaper scheme to make their images or renders.

Maybe you could set the hobbiest renderer to 2 hours render time max, then not allow them to render again for 24 hours.

Thanks
Jon

DA Portfolio - http://jonj1611.daportfolio.com/