This really depends on what condition your window is in. If the frame and the window mechanism is fine but the other bits around it are failing i.e: Blown Double Glazed Unit, Seals or Gaskets Perished you can hear road noise or feel a draft, furniture warn out, hinges needs replacing or adjustment? There is a chance you can just replace those.
For the environment and your pocket repair is the best option where you can!
We will always be transparent with you a suggest the best way to go, we drive no hard sale and our survey of your job is completely Free! Contact us now.