The problem with this is that Resolve won't run on ATI graphics cards, only nVidia. Now that Apple switched over to integrated ATI cards, it's almost impossible.
The industry standard for color correction is DaVinci Resolve. If you want to get really creative, there's nothing better...it's pretty expensive though ($1,000)
http://www.blackmagicdesign.com/products/davinciresolve
Seeing as everyone seems to be ignoring your question of cost, I may as well chime in. I have a production company and a $2M per occurrence/$4M aggregate policy that I pay yearly for to issue unlimited certificates. My premium is $2,407 per year.
You can also invest in a matte box that you can use with filters, that way when you change a lens you don't have to attach/detach filters. You can get some pretty decent matte boxes from china on ebay for around $150-200, then just grab some 4x4 filters to go in them!