Two things you must have - Tell your Parents, Tell your Girlfriends, Sell your pet.

[6S.Tamat]

I have freetrack and with a little expense of 20 euros i let it function very well. It is almost two years now and nobody of my wing never felt the difference with the other people with Track ir.
So if you can manage to build a little cirtuit like the ones that are builded by children it is a good choice.