It may be $1.50 but how many truckloads did they buy to get that price! The last time I checked everything down to the little salt packets are shipped by McDonalds Corp. The stores may be franchised and the operator can pick and choose equipment, but they are stuck with what corporate ships them for food based supplies.
It's like any good business, the coffee may have been more expensive but they bought a bigger quantity to get a better price break. In 2004 they had 31,561 stores through out the world. I bet they get a better price break then Starbucks can get on supplies.
So before you go saying their coffee cost a $1.50 figure out how much it would cost you before they bought it in quantity!
As for your statement: “I'm very clear about the original question. The reason to pick equipment is capacity, convenience, cost, reliability, MTBF or it could possibly be some misunderstanding about the coffee itself.â€