Are Johnson Matthey 1oz bars with 'A' serial numbers worth a huge premium?

This local fellow has some Johnson Matthey bars he is claiming are extremely rare and valuable to the point of $50 per ounce. I want to lol, but, heck, what do I know about anything? He sent me pics, which I could post, but they are exactly like these:

Except their serial number begins with 'A'. I can find nothing about this on

And figured this guy is perhaps complete BS. But, again, what do I know. Any of yall able to confirm what this guy is saying?