Posted: 14/11/2014 at 16:53
Can I ask why you want to know? I'm a curious sort of person
And to answer the question, it all depends - I've been known to come away with a plant for £3 from the Nearly Dead shelf, or a few fibre pots for £1.99 - at other times of the year I can walk away in a sort of stupor having spent £75 or more on some plants and compost.
If I'd got room to plant a few trees and some more shrubs I'd spend £100s.
Don't think you can average it out and end up with anything meaningful - there are so many variables.