the.com/bait and switch

means A deceptive sales or marketing tactic where a buyer is lured in with an attractive offer, then pressured toward a different, usually inferior or pricier, option once they're hooked.

from A term from mid-20th-century American retail and advertising jargon, describing a swindle as old as commerce itself: a shop advertises a cheap item to pull customers in, then claims it's sold out, unavailable, or defective, steering them toward something costlier. 'Bait' is the lure that hooks interest; 'switch' is the sleight-of-hand swap once you're caught. The practice became common enough — and harmful enough — that U.S. consumer protection law (via the FTC) explicitly named and banned it by the mid-1900s, cementing the phrase in everyday language well beyond the sales floor.