After having experience with one myself.. never again. Even thought it changes the gullet of the saddle, it doesn't change the spine of the tree. Therefore it's almost always going to be too narrow or two wide, unless it fit's your horse perfectly.
I constantly had problems with the wintec I had, my horse HATED it, he'd buck and buck because he was obviously in pain. Got rid of it, got a nice used beval that I had check by a professional saddle fitter to make sure it fit and his behavior completely changed.
For your price range you can get an awesome used saddle, without a changeable gullet that will be much nicer on horses backs.