HKgal: Sorry to dissapoint you, but Body Shop goods at London Airports are no cheaper than on the High Street. They appear cheaper because Body Shop goods are cheaper in the UK anyway.

As far as airport shopping goes, stick to 'Duty Free' which is only Alcohol, Tobacco and Fragrance.

Anything else will just be 'tax free' ie. no sales tax. As a non-resident you will get a much better deal on the High Street and claiming you sales tax back at the airport.
MF