That’s why so many teachers organise ski trips for the School!
Try cheaper destinations like Poland (yes) & Bulgaria. Italy and Austria can be cheaper, just pick a grim purpose built resort. Leave Switzerland and France alone, way too expensive, even the cheaper places.
Have you thought about driving, and staying further down the mountain and then driving into the resort each day? Can save quite a few £££’s. If you also go self catering, then buying bread etc in the local supermarket and then eating on the slopes can also save a bit, as is not buying drinks,snacks etc up the mountain!
Good luck….