It’s pretzels, not nuts, and on a Band 4/5 you get tend to get two bags, not one.
On a more serious note, I’ve never seen MS anywhere near as cheap as BA. Appreciate I wouldn’t be on a corporate deal, but still, if customers overall insist on choosing on price, we’ll be given cheap stuff.
Similarly, I bet SIN-HKT was priced well above the cost of a BA flight of equivalent length, most probably even if you include a Pret meal in the equation. Different markets mean different market conditions.