Is it worth spending money on expensive cookware?

Every week a Guardian Money reader submits a question, and it's up to you to help him or her out – a selection of the best answers will appear in Saturday's paper. This week's question Our big family goes through a cheap non-stick frying pan every year, and each time I buy another I wonder if it's worth spending £80 on a decent one. If I do will it really last the 20 years they claim? I am told cast iron is better, as non-stick is bad for you, but do they work? What are your thoughts?