Repair or replace windows

Chances are it will be an easy fix. Change the hinges or locks which should be cheaper than buying a new window. I would weigh up how old the windows are and as long as the seals are Intact and the window isn't draughty it could be worth repairing. If the windows are fairly old it would probably be worth spending that little extra and get the windows replaced with new windows with better thermal efficiency. Especially with the energy prices rising.

I would be minded to try replacing the handles on each window before deciding that they needed replacing, if you want to try and avoid the cost of new. The existing handles will be attached by two screws. They may be under a small cover that can be flipped off. You need to raise the handle to access one of the screws. It’s quite straightforward to drill the lock out if the handle won’t budge. You can get a new handle for less than a fiver if you approach a trade outlet (I use Glassolutions in Cardiff),

I don’t think it would be cheaper to get an all new window , it sounds like your hinges have corroded You can sometimes ease them open a bit and spray some lubricant in there to free up the hinges. Unless the handle is broken