How much to have a highland terror bitch spayed?

[Chippingnortonset123]

In three months time. She has a permanent health condition which is managed by prescription diet.
I have rung both her vets but would appreciate experiences.
It should not take an overnight stay.

There will be a massive range depending on where people are in the UK and usually cost of spaying is weight dependent so without knowing her weight it really is a stab in the dark.