Auctions are more for pet and production or cages and equipment, if you really want to scrub and bleach the sin out of everything. I used to buy my eating eggs there too. Just can't beat a $0.25 dozen of eggs if you don't have any layers (heck, even if you do!) For me, I'll pick up scovies at some point in time, and a pekin drake, but just about everything else is off limits until I get into rabbits. My cornish cross, my BBW turkeys and my pekins all came from auction (pekins were eggs). They were all hatchery birds and in the case of pekins, hatchery quality. But when you're just starting a self-sustainable flock for your dinner table, you don't really care if the eyes are the wrong color, the beaks are a smidge skewed or whatever.
As for bantam pets? Try OEGB or serama as well. LOVE those little birds, but if you free-range, watch for hawks and don't step on them. Also watch for birds flying to get on your shoulder! They're like puppy dogs, lol.
