Here, he store was giving you 11 ounces free. They will only get reimbursed for 48 oz. from the gov’t.
The government pays more for 48 ounces than I pay for 64 ounces.
I was once in a store and saw that the most expensive eggs were the medium size. When I asked the manager about the pricing he told me that almost all medium eggs are sold under thw WIC program so he charges the maximum allowed price, for the other sizes he had competitive prices.