Coupons and vouchers

So I have this yazoo milkshake voucher, printer only allows maximum 3 prints per item but some company only prints once, so I photo copy them sometimes , just don't use all in one go cos they have same code numbers. Noticed the date of expiry is October, so I found rather than buying 1 400ml bottle (50p - £1)you can buy 4 little bottle packs 200ml (£1.60) voucher says to value of £1.60. Depends how you look at it cus it means you get an extra 60p off your other shopping or 4 drinks and more suitable size for my kids