I got my first keg from a beer store, whom I asked if they had any kegs I could buy outright. The keg they "sold" me was in really good condition, and only cost me $30. I'm looking to get a second brew kettle, and I feel like the way I got this first one was shady at best, considering the cost to the brewery to manufacture a keg.
What are some good sources that are on the level for obtaining a relatively low cost keg for kettle use?