Since joining Ibuildings last november and getting a mac, I've bought more software than I ever did in my live. However, these are not the prices you pay for the average windows software. Most of these (independently developed) software is in the range of $15-$30, a price range I feel is reasonable. And most of these software packages do a specific task, and they do it so well that there is no open source alternative that does it in the same good way.
But even when I was still a linux user, I spent money on software. IMHO, there is no editor that does XML as OxygenXML does, so I bought that one. I am a disaster with regular expressions, so I bought a license for RegexBuddy as well. I also paid for Crossover Office.
So yeah, I've paid for software. Usually when I need something I first check if there is an open source package that does what I want, but if there is a commercial package that does the task much better... I pay.