We went there for some "polyfiller" type stuff. Eventually the man said why not use plaster? We did not have a problem with that except we explained that it was just to fill in a few small screw holes and we didn't want a 5/10kg bag. He propmptly went to a bucket out side and sold us about a cupful in a plastic bag for a pittance.
Used this shop a few times and it is excellent and a real Aladdin's cave.
Teresa