I think you can successfully repair the regulator with JB weld under the condition that you never use the window again. It will ALWAYS break again if you lower/raise the window (maybe not the first time...).

You could fix the regulator and remove power at the motor so that no one can accidentally operate the window.

If you want a functional window spend the money and get a NEW regulator.

__________________
Daily Driver: 02 E430 4MATIC
In the family: '03 E500 // '04 ML500 // 64 220SE