I would just like to add that a real hand made carpet is likely to cost £1000s, not £100s, and even a textile technologist such as myself would be hard pushed to tell the difference.

During my visit to Tunisia I have to say, I've heard quite a bit of technical rubbish spouted from tourist guides who are trying to persuade their punters to not buy in the local market but to wait to they get their preferred carpet shop (since they are most likely on commission themselves).

Yes, the carpets are very beautiful and lovely quality, but they are unlikely to be hand made as it is often implied - just be aware that's all.