What's wrong with your current one? Not working at all? Window cable broken? Plastic parts at the end of cables broken?
Window mechanisms are rather easy to work on, just needs some basic tools, angle grinder and electric drill. As long as those two plastic parts are fine, repair costs are pennies, if at all, if they are broken, then some mechanism has to be cannibalized for parts.
Last year I made one power window mechanism for my mk2 golf from original manual + B3 audi window motor [basically the same thing as should be in golf] - just one, because I'm too lazy to finish my power window conversion
