Hi there,
I’m not sure why the terminology was so confusing there, the only prices paid are for successful API calls. Although we have no plan available publicly listed, Mashape allows us to do a flat rate for you if you’re serious about the volume, we can do it for $200/month. I don’t think any serious competitor can approach that but if you get a serious alternative do let us know. We’ll also need a bit of time (a couple of days) to add extra servers to the infrastucture to accommodate you. Perhaps you could try out 10k requests and see if we’re supporting all the TLDs you require to the quality level you expect before diving in.
Let us know what sort of use case you have in mind (helps to understand what sort of data to provide and which quotas/limits we will hit as certain TLDs have lower, stricter limits).

Thanks,
Mark