If I ran a bakery, say, in New York City in 1900, I could send a boy around to the nearest five bakeries and get answers within an hour. That would be "real time" within that context, in the sense that customers would not respond faster than I could gather the information.

If I ran a stall at a market in, say, 1500s England, selling potatoes, I would know what price my competitors were selling potatoes for, faster even than an hour.

If I ran a gas station at an intersection, I could see at a glance what price my competitor across the street is displaying.

With current stock market tools, I can see the backlog of both buy and sell orders.

When I go to sell a house, my agent tells me the asking prices of comparable houses that are currently for sale, as well as the actual selling prices of comparable houses that have recently sold.

This is how markets are. Sellers know each others' prices.

So the only thing different is your "grabbing coffee afterwards" claim, and so far, I have seen nothing of substance to back it.