It is not unheard of--in fact, the OPPOSITE of this is unheard of--for startup (and TC companies are still in startup mode) software companies to attract beta customers with VERY favorable pricing and terms. You want referenceability: the lighthouse account who will stand up for you and sing your praises. And whatever Wave **might have charged** is negligible compared to the amount of PR value that this turnip has bled.
Even well-established enterprise software companies will play games when they're trying to break into a new category: giving stuff away... deep discounts... "rip and replace offers" that defer any sort of compensation... etc.