RE: building feeders
If you search hard you will find them 55 gallon barrels for free.
If you know anyone that works at a school sometimes a teacher can get them from Coke Cola or Pepsi for free if they say they are using them for recycling cans at school. The drums hold syrup so it is safe for the deer.
My brother works at the veterans hospital and he picks them up outside of his work. He is on the grounds crew so for him to pick them up is know problem. There they have to clean them before setting them out to be picked up.
A friend of mines father is a butcher and he gets them from a vets clinic where teat soap is stored in them. He then brings them to the local butchering plant where they have a high pressured steam sprayer and he cleans them out.
Down south it must be a problem with extra critters getting in the feed. Up here they are all sleeping through the winter. They don't come out until it gets warm which is around April.