I am the dairy lead at a very busy store (not a marketplace mind you, so I don't get the hours I need) and I can assure you it is definitely not worth it... I would definitely try to be frozen lead or Nutrition lead if possible then work into an actual department head (grocery/produce or drug GM).
Dairy lead does everything that an actual department lead does and gets a whopping .50 cent raise instead of the actual department heads who get minimum $20/hr in my district...it's disgraceful.