Mate, when it comes to buying your goggles, buy brand new. You can't put a price on protecting your eyes, and you don't truly know the history of a lens in a set of pre loved goggles (how it's been cleaned, whether it's been left on the back shelf of a car in direct sunlight, or in the boot next to a petrol can etc). It's exactly the same principle for buying a motorbike helmet. We all like a bargain, but some things just aren't worth saving a few quid for. Oh and don't go cutting the little label out of them either, or the chin strap if there's one present. The moment you do, God forbid the gogle system fails safety standards in any way when you are using them, all warranty becomes null and void......due to them being altered form the manufacturer's original design. Leave the little tag alone, and simply zip tie up the strap with small zip ties. Might seem anal I know, but it's fact.