Just because you buy something at a bargain price doesn't mean your rights are diminished in any way. Your consumer rights remain the same regardless of the time of purchase. If you buy goods in a sale or at a reduced price you have a right to expect that they are of merchantable quality, fit for their purpose and as described. You may be entitled to have the goods repaired or replaced or your money refunded if the goods are not as they should be. The European Consumer Centre advises that if things go wrong you should keep your receipt or some proof of purchase.