http://www.ctd.northwestern.edu/numats/program/fees/?tag=Parents
This is a link to the fees through Northwestern. Other schools offer it, and sometimes smaller schools that aren't part of the big testing program (like CTD or CTY). The downside is that you're not connected in to their programs or awards ceremonies, but we wanted it more for our own personal info and for school advocacy. Last year, we took it through a local university and it was $50. If you look around, there are other sites.
http://www.act.org/explore/ests/centers.html - this link will tell you the talent search sites.