It is an reckless business practice to not have the monthly price locked down, with strong contractual protections. Sounds like Correnti didn't negotiate well and are now finding out.
A lot of open source software uses this model - free for everyone, but if you're a company that wants support then you have to pay for it, and that covers the development for everyone
Are you sure this is negotiable?
Price on things like kitchen appliances, furniture often negotiable - you just have to ask.
My wife: (good customer) if I guy two pairs of shoes I want 2nd pair at 50% - them "ok"
My wife: what will you give me if I buy this (expensive briefcase)? - them "$100 gift card"
I got an extra $150 of a sheepskin coat at a going out of business sale just by asking