49er said:
Can I just say, you did not have a contract with him. Legally you had made an "invitation to tender" which he subsequently declined. Legally entirely ok.
For good order, I would note that your advices are not entirely correct 49er.
It is the seller or shop who, by setting out goods with prices on them is making an 'invitation to treat'. In essence, this is an invitation for a potential buyer to enter into negotiations. The seller does not intend to be bound by the prices of the goods on offer - the actual contract of sale occurs when the seller accepts the buyer's offer to purchase the goods at a particular price. The buyer is quite free to make a reduced offer or a conditional offer and the seller may accept or reject this.
In the particularly curious case of the 'razor without the discount', IMO this is how the law would construe the situation:
1) The seller sets out the razor to be sold at a particular price.
2) The prospective buyer responds with a conditional offer to purchase the razor subject to a particular discount being applied.
3) The seller accepts the conditional offer (irrespective that this is done electronically by an ordering system) and hence a contract of sale has been concluded.
4) Upon reflection, however, the seller decides that he subsequently does not wish to accept the buyer's conditional offer and cancels the contract of sale.
5) Generally, this would be construed strictly against the seller as a breach of contract, and the injured party - the buyer - would be entitled to recompense including
inter alia, specific performance i.e. the sale to go ahead at the conditional offer price.
But that is not the whole story. In this case, the seller made it clear to a select group of potential buyers that no discounts would be offered on the goods i.e. the particular razor in question. In law, he would have good grounds for a defence to show that he never intended that the goods be sold at anything other than their advertised full price and that the entering into a contract of sale with the buyer (who made the conditional offer) was a 'mistake'.
In practice, however, and for pretty obvious reasons, the law does not look favourably on sellers (or buyers for that matter) trying to claim that the entering into a contract of sale was a mistake. Clearly, this would open the floodgates for people who felt that their part of the bargain was not (with the benefit of hindsight) favourable and consequently the fundamental concepts of contract law (including, in old money - a man's word is his bond) would be thrown into disarray.
Disclaimer - I am not affiliated with either party in this matter and furthermore make no warranty or representation as to the accuracy of my advices, which are given in good faith only and should not be relied upon whatsoever!