Even from the food cart on the corner, your morning iced coffee will run you $1.50, maybe $1.25, and it’s usually watery and/or warm. The Chelsea café Champignon’s $1 iced-coffee special, available only in the summer, comes in a normal-size (sixteen-ounce) container and is reliably rich and icy. 200 Seventh Ave., at 22nd St.; 212-366-4410.