Is it reccommended for using with freetrack?
I don't need for sure, I found one post in 2011 of someone who wanted to use it.If it is realy cheap, why don't give it a try.
What you want of a webcam for freetrack is that you can disable all the auto-functions like auto-zoom, auto-exposure.
Removing the IR filter is a must?
It depends on how strong the ir-filter of the webcam is.If you can block the normal light and still be able to see the dots of your leds, you don't need to modify your webcam.I have a MS vx3000 webcam, it has an easy removeble ir-filter maybe yours also.But I realy don't know how hard it is to remove for sure.
So, if it is realy cheap, and you are not afraid of a little experimenting, give it a try and let us know how it works out.Is the cam good for freetrack or not.
Good luck