“All of this is not true for milk.”
Does the CY come from a “part time” CY farm or a full time one. A “part time” CY farm is one that is “rented” for a special CY run. A team of mashgichim have to 1st kasher all equipment that comes in hot contact with the non cy milk and all storage vats that store milk for 24+ hours at a time. Once done, one or more of the team remains on site at the farm during the entire CY production run which may be several days or several weeks. There may be several such productions a year to ensure a continuous supply of fresh CY milk. this costs money. the mashgichim dont come from a gmach. A full time CY farm doesnt have the kashering component, but, it should be pointed out that most farms are not situated near a heimishe neighborhood, and you have to make it worthwhile for someone to live in such a place all year long. Those who live in these far flung places are not doing it out of the goodness of their heart and are not a gemach and they have to be compensated for it.