1st class return train tickets x2 London-Norwich paid £87 accept £50 +

I have advance tickets for London Liverpool St - Norwich via Cambridge travelling 1st class as follows: London- Norwich 02/03/12 at 1500 Norwich-London 04/03/12 at 1103 paid £87 but no longer need to go to Norwich and have wasted my money. found my tickets are non refundable. Will therefore accept £50 for them if anyone wants them. Can post if they are paid for by paypal, special delivery.