Contract problems

Jenny received a circular from Beauty and the Beast Hair Salon advertising massages and manicures for $$10.$ Realising that this was an exceptionally good deal, but not surprised because she knew that they had only just opened and were running a number of good opening specials, she rang and made a booking. When Jenny arrived at the salon she was told that there had been a mistake on the circular and it should have said $$100.$ The manager of the salon explained that this was still a good price because normally a massage and manicure would have cost $$150.$Jenny was furious, as it had taken her $30$ minutes to get to the shop by car, and if she had known it would cost $$100$ she would never have made the booking. Advise Jenny.

Would your advice have been any different if Jenny had the massage and manicure before being told that the cost was $$100?$

Would she have to pay the full?