marjon, I am not a Webley expert, but I do get a lot of these through my hands. It depends what model it is, the early tinplate grip ones are more collectable. Then you get the second type with plastic grips that can have some "plum" coloured fittings. The last model has a larger diameter chamber casting at the grip end made from zinc alloy which are usually cheaper. The whole group can range from £70 to £200 depending on type and condition. Below is one I repaired yesterday, think the guy paid £170 for it. The guys on collectables would have more knowledge.
Baz
https://i.imgur.com/JM3FyDT.jpg