I suppose that depends on what he produces and what he wants for it. Sadly, I wouldn't pay too much, but only because I don't know how much I'd use it. Definitely like to have it, though. That's part of my frustration with the state of Amiga Land, the lack of really good programming tools. I'd love to have Java or Mono, for example...
Amen brother.
I'm cross compiling everything and debugging with printf's and UAE. It's not fun.
I'd pay well for a good IDE with a GUI debugger. Visual Studio spoiled me a long time ago so I find even the Linux IDE's lacking in many ways, but anything is better than the current state of things.