Duty Free Goods
All passengers no matter where they are traveling can buy Fragrances or other beauty products,luxury items such as jewellery,watches,bags or cameras and confectionery at tax free prices.
As mentioned before it is only tobacco and liquor that is restricted.
However you can buy liquor at duty paid prices if you wish.LHR used to offer tobacco products at duty paid prices as well,but whether they still do I don't know.
BHX used to as well but there was not much of a market for cigarettes at UK prices,so that experiment did not last long.