Try Scool – GCSE and A Level
A Super purchase would be Economics Through Diagrams AS and A Level Andrew Gillespie ISBN 978-0-19-918089-9 available cheaply on Amazon – if you are only weeks away from exams you may need an expedited next day delivery which would increase the cost.
A Google search on
How many Economic Diagrams are there? – Google search results.
Careful as these are mainly A Level or beyond.