Discounting of Cheques

Q: A certain person has a PDC (post-dated cheque) but needs the cash urgently. He approaches someone to give him cash in lieu of the cheque which the person will cash later on and receive the money. The person agrees to give him the cash in lieu of the cheque, but is only willing to pay him an amount that is less than the value of the cheque. For example, the cheque is for R25 000 and the person agrees to pay him R24 000 cash. Is it permissible for him to accept the R24 000 in lieu of his R25 000 cheque?