Thanks for the comments.

My competitors (uservoice.com, ideascale.com, and a few others) charge a similar base fee, but they both have a tier-based pricing structure. I'm shooting for more of an a-la-carte model that lets my customers choose which features they want.

If, after a few months or so, I find that my pricing is too high, it's a lot easier to lower prices than raise them:).

Thanks again!