The prospective buyer, by offering that price is himself the offeror and his offer, if accepted, create a binding contract. 1
For this case, James just noticed a gold watch with a price tag of 25 hence it neither does nor compels the store person to sell the gold watch at that particular price. The price tag with the gold watch was just inviting others to make an offer of their own on how much they are to buy the watch. A binding contract would have been created when the store person (Elizabeth) would have accepted the offer made by James since the price with the gold watch was just inviting customers to make their offer.
Normally, invitation to a treat is used to request expression of interest from the customers. For this case, any product with a price tag does not compel the store person to sell his product at that price but requests, an expression of interest from the customer to make their offer and binding contract of sale would occur when he agrees to sell at that price. 2
Invitation to treat must be distinguished from an offer. This is because, invitation to a treat invites for people with to make on an offer whereas, in a offer, the offeror make in an offer and just wait for people to accept that offer.
In order for a co ...