kchika: Yes, some wines are cheaper in HKG. But others are not, especially those in very limited qtys. which would need to be shipped over from the UK. Dom Perignon is a staple in HKG, but e.g. a single bottle of Chateau d'Yquem 2004 vintage (which I saw on my last LHR/ZRH trip in April) was significantly cheaper in UK duty free than in HKG. It's just the typical supply/demand thingy with economies of scale (DP in high qtys. is cheaper; rare wines are more expensive to cash in on "collectors' premium").

A lot Bordeaux investment wine (above for drinking only) is actually cheaper via some brokers in UK London City Bond vs. HKG where they inflate prices artificially despite 0% tax on wine - even when adding air freight or refrigerated ocean container shipping to HKG. I buy full cases of rare wine, get them shipped to HKG and sell them here in HKG to profit on arbitrage (and earning miles when charging on CC ).

sxc: Yes, appears that it was another fare than W/T/E. I didn't bother to call BA to check further for the exact fare class, as connection schedule was already not suitable anyways. I only briefly logged in to BA website on reserved itinerary on WT+ and saw that the BA website did not offer me to upgrade with miles - basically confirming what our TA claimed.