These BERU glow plugs are by far the most long lasting ones I've used on 200/300tdis. In fact, once purchased and fitted, I've never had to replace them on any Defender, Discovery or Range Rover...ever!
Forget penny pinching on cheaper aftermarket alternatives which can last as little as a few months (and sometimes don't even work out of the box) - You'll just end up spending more in the long run as well as being let down as soon as the weather turns cold.