. . . at around the same price, or had they put the wrong price on it and realised (but not told you)?
Various other threads here on mispriced items and if you read up on "Invitation to Treat" you might find they don't HAVE TO sell at the price listed.
Some places do as a gesture of goodwill.
It would have been nice of them to say "Oh, we got the price wrong, sorry but we can't sell it to you at the price advertised"