When it comes to middleware, it isn't the cost of THEM to develop it, what matters it the cost it would take for you or your project to implement the same functionality.
Hmmm... They're asking a LOT of money for a project of not well-known people. "We're... It doesn't matters really. Point is, we want a quarter million dollars please."
Though their project looks like it could require such amount of money, by that I mean it may be too ambitious.
Could you implement the same thing, have it debugged, and have it available today, for less money?
Is it cheaper to use theirs --- which is available today at a known cost --- than it is for you to spend an unknown number of months re-inventing their wheel, debugging it, refining it, and supporting it, at an unknown cost?