I asked a question earlier about what cheap/free screen reader software was available, but now I am curious as to the usages statistics of all available (not just free) screen reading software. Is there any place that compiles this data?
My concern is that while there are some up-and-coming free software available, that not many people are using it. I'm trying to see if there's a justification for buying an expensive software package or if using a free software package is "good enough" to test our web site accessibility.