No the item is an invitation to treat. When you go to buy it you make an offer to buy it. That offer can be declined or accepted by the retailer.
Offer and acceptance and consideration the three parts of a contract, the invitation you are looking at is not.
http://www.gillhams.com/articles/200.cfm
http://www.tradingstandards.gov.uk/c...V1011-1111.txt
The case law that set this out is Pharmaceutical Society of GB v Boots Cash Chemists Southern Ltd back in 1953.
http://en.wikipedia.org/wiki/Pharmac...outhern%29_Ltd.
http://en.wikipedia.org/wiki/Invitation_to_treat
Might also help