the $30,000 room is the food processing room that turns milk into cheese and butter. the $60,000 room is a room that milks your cows for you. you put them in the room and it milks them
I'm not sure where the items go from the milking room, but I do know that after you send your cows in there several times they'll get in the habit and learn how to do it on their own. Then you never have to milk your cows again - whenever they need milking, they essentially milk themselves. That's the life of a lazy farmer.