Yep but the cost of refrigeration is built into the milk.
I fully expect business to implement this system as soon as they can and market it as a "cash discount" where you get 5% off for paying cash or something of that ilk.
We will see how it turns out. But expect people to be pissed when it was put on them.
Apparently when they put this into practice in Australia they were charging outrageous amounts (like up to 20-30%) to use a credit card at every retailer no matter where you went.
Someone feel free to correct me but I would assume the cost of refrigerating the milk up to delivery is built in to the milk. After that, the cost of keeping it cool in store would likely fall in to operational costs and be accounted for in the standard markup on all goods that the store has. The fridges need to run whether people are buying the milk or not.