1
general::
Deceive, swindle, take unfair advantage of, as in He was just selling you a bill of goods when he said he worked as a secret agent, or Watch out if anyone says he wants to trade bikes with you; he's apt to be selling you a bill of goods. The bill of goods here means "a dishonest offer." [c. 1920]
American Heritage Idioms
2
general::
Phrase(s): sell someone a bill of goods
Fig. to get someone to believe something that isn’t true; to deceive someone. • Don’t pay any attention to what John says. He’s just trying to sell you a bill of goods. • I’m not selling you a bill of goods. What I say is true.
McGrawhill's American Idioms And Phrasal Verbs