Woah there, your post is misleading and I want to make sure no one is confused as a result.
You said you inquired about Voxeo/Tropo but the pricing you mention above has absolutely nothing to do with Tropo.
Tropo is 100% free for development use - always.
Production Tropo pricing starts at 3 cents per minute with free second-leg (connected) calls, free voice recognition, free high-quality speech synthesis, free 24x7 support, no minimum, and no port limitations.
Thanks for the info. Looks like I should re-evaluate things as at the time Tropo seemed to be a coming-soon/developer-only service that didn't have details around production pricing nailed down. The Prophecy IVR info scared me into thinking that Tropo might have similar limitations.