They are cheap compared to what? They are more expensive than the highest tier of Labview licensing (!), way more expensive than the highest tier of Visual Studio (MSDN) subscription, Adobe CS, AutoCAD... I'm not cherry picking, they're literally the most expensive subscription based commercial software I'm aware of.
Hopefully it's apparent because of the extremity of the comparisons being made here (a production SQL Server deployment is more expensive than a Qt seat, yes...) how high Qt's per-developer cost is today.
In my naivete I would have said a decade ago that a single author of traditional shareware-type stuff should just include their source code. After seeing what happened to the Paint.Net guy, people taking his work and just renaming it (as well as removing credit and license info) and reselling it, I'm afraid closed source is still the way to go if you want to not get ripped off while distributing Windows consumer software. So the high cost of the Qt license becomes relevant there.
It's fine, it's their right to price their software however they like, etc etc. It's just a scary commitment if you want to experiment with putting a small product out there.
> Qt more expensive than Visual Studio Ultimate?!?
They're just calling the top VS tier "Enterprise" now. The subscription version of VS Enterprise (which includes office and Windows all the way back to XP) is $3k a year now.
What are they "pretty cheap" when compared to?