Cheapest Metal Corefor A Scooter Where Can I Buy (on The Web) The Cheapest "metal Tester"?

Where can i buy (on the web) the cheapest "metal tester"? - cheapest metal corefor a scooter

Are there any products offered for sale around the test site for gold - silver - bronze - and so if not, where is the cheapest to find a "golden K. Tester? NO EBAY - I checked