If this can replace a standard debugger I wouldn't even blink at a $100 dollar price tag.

I'd want testimonials and videos of it in action, but if anyone I trusted vouched for it that price would be a no brainer for me.

I would suggest something along the lines of YourKit pricing which seems to be industry standard for the most part.

Also their personal license which isn't advertised heavily is $99/yr which allows for commercial use but must be paid for by the individual rather than a business entity. I like this license because I like to take my tools with me and doesn't make me beholden to purchasing/procurement departments of the companies I do work for.