I loved the little dome-shaped Goldencups with the flat bottom and the silver foil. They were WONDERFUL. I also remember the jingo:
Goldencup by Mack - in - tosh!
They used to be 46p when I were a lad!
It's true though. I too have an abiding memory of them being expensive and an occasional treat.
I must confess that I loved the big bar the best, contrary to others on the site.
Then again less isn't always more.