The taxes via London are crazy since they add on a "luxury tax" for Biz and 1st class tickets even if you are just upgrading to a premium cabin or redeeming miles for a "free" ticket. The taxes on a "free" business class ticket can be more than the economy fare during the off-season!! They claim that it helps pay for "Fast Track" but I've found that on some occasions the "Fast Track" is no quicker than the standard line.
