I live in Miami, that is no secret. I visit the DR every three months or so. I buy bananas in the Barahona market 3 for ten pesos. Sometimes I get the same price from guys in a truck. Once I bought three bananas, peeled one and it was strangely small, and the seller told me "no coma eso" and gave me a couple more for free. If I wanted to eat more than three bananas, I bet I could get a bigger deal, but 10 pesos is a quarter. Big deal.
The only way to prove or disprove what MiamiDRGuy says would be to follow him about and verify what he claims. Personally, I see no reason to do this. He may be an extraordinary banana salesman. Perhaps he has a location where many banana-starved European tourists come and buy their daily banana breakfast from him at European banana prices.
For all I know CC may also be an expert in the purveying of the popular yellow fruit. My observation is that everyone that has a business believes that their way of running a business is the only way. This tends to be untrue, in my experience. As they say, "El mundo es ancho y ajeno", and one size never fits all.
This is not an argument that anyone can actually win or lose. So why bother to have it?