Ok, I know I'm not in law school yet, but this cannot be correct. Although I agree that a newspaper advertisement does not generally constitute an offer but is rather an invitation to bargain, that is not where this hypo ends. The offer is by Jane to buy the car for $6,000, which Mary happiliy accepts. Offer, acceptance, consideration. Done. There may be other more subtle reasons that the contract was appropriately revoked, but I just can't buy the "newspaper advertisement does not constitute an offer". Someone set me straight.
the offer would be the tendering of the $6k, which Jane never did. And Mary would accept by actually taking the money
Why? What if Jane never shows up with the money, would the courts force this sale?