A dining chair is a miracle of engineering so as to not collapse and fall apart when a 150 lb to 250 lb + person sits in and leans back etc.
I once talked to a rather smug and unscrupulous antique dealer who bragged of getting 4 or 5 Hitchcock chairs from an old couple for $15 to $20 a piece when they were worth $1200 to $1500 a piece.
It's hard to believe, but some of those chairs really are worth that much. That poor old couple got ripped off. What a scumbag! :-(