My grandfather was born in Indian Territory in 1905, in what is now called Oklahoma. He began riding the rail road from somewhere in OK. to Dallas, selling newspapers, apples, candy, etc. as a teen.
When he got to Dallas, he would hit the coin shops and buy any odd looking coins. Nothing of value, just different looking, would buy them at face value.
When he got back on the train, he would slip one of the odd coins to a customer when making change for a sale. Then he would pull the coin back and tell the customer he did not mean to use that coin, it was valuable, rare, whatever. He would then negotiate the sale of the coin to his customer at a slightly higher price, and make a penny or two off of a nickle that he paid a nickle for earlier in the day.
I still have some old coins, Confederate money, fractional bills, etc. that my grandfather gave to me as a child.
He went on from riding the trains to working on them, and his job was considered high tech at the time. I often marvel at all the change that man saw in his 80+ years on this planet. Both world wars, the death of the steam trains,the birth of air travel, space travel, television, computers, etc.
And the change is still occuring.