How much is a used rolex 62523h 18?

Again people are just making assumption's here these watchs only go for this kind of money if they come with the cetificate without a certificate of authentication or original reciept of purchase then it's not worth a vast amount you'd have to take it to a repitable watch shop or jewelry shop and have it checked over to make sure it is genuine and ask them to put in writing to prove this, i usually do with for around £30- £50.