Isn't there some old adage about how if you can't afford something you aren't the target audience. At the larger companies I've worked at you didn't even need approval for 15k/y.
This was for a company with just under 300k employees - you need approval from multiple people for everything.
From the marketing, blogs etc, Ubuntu Core does seem to be targeted at everyone, not just people that would drop $15k/y like it was nothing.
It's almost like a trap - it sounds perfect for IoT, so you start wasting your time building a PoC, and then much later you find out about the costs. And as another commenter mentioned, they also charge you for doing updates on top!
At the two larger companies I've worked at (~1,000 and ~50,000), I've been explicitly told that I cannot sign any contracts without getting it approved by the legal department. Furthermore, all software purchases must go through the approval process.
