If I buy a product on-line but the price advertised is incorrect?

If the price was obviously wrong, say 99 p for something that should be 99.99, then they are not bound by it. Otherwise, you had a contract and they can't cancel it.

Under the law a posted price is only an "offer to treat" and cannot be enforced either by the buyer or the seller until the sale is agreed. This is why you can see an item in a shop window at one price but the shopkeeper is entitled to charge you whatever he wants if you decide to buy it.

BUT under contract law if an offer is made and then accepted the contract must be fulfilled. If one party defaults then the other party can sue them for the lost value of the contract.

In your scenario an offer was made (you sent the money) and it was accepted (confirmation was received). The second email said that the order could not be fulfilled - so you should get your money back. That is all fair enough.

The second email saying the price was wrong is a peculiar one. If the order could not be fulfilled (for any reason) then it doesn't matter what the price was - you are not going to receive the goods anyway!

Basically, the contract has been cancelled by the vendor because they cannot honour it. The reason is really irrelevant. They are returning your money.

You could sue them for any additional expenses that you had incurred, providing that you can prove these were as a direct result of making the offer to buy and the cancellation of the order, but it's probably not worth doing that unless it's a substantial sum.

Probably yes.

Most online retail sites have a disclaimer for this in their terms and conditions. It has been found to be of legal validity.

Sorry.