Nice set you have there!
This is original Big Big Train made in England. The box and contents looks in good shape.
For a collector (like myself) it could be a very nice addition to the collection.
Value is very personal and if it needs to be shipped it will involve costs.
I have seen sets like these offered for over 100 GBP. But shipping it with solid packaging will cost probably an additional 50 GPB?
By the way: I took the liberty to correct the orientation of the pictures. Hope you don’t mind.