Is this unreasonable?
It's clearly extremely unreasonable, unless you never actually plan to support more than 10 simultaneous users.
These guys want several thousand per month for this level of service (and are asking for more, reaching into the 5-digit range now)
The appropriate thing here is to call them and ask "WTF are you morons doing". Maybe they can get it fixed. Probably not.
The "speech recognition+AI assistant" market has boomed recently so I'd expect there to be a few alternatives at least.