Unfortunately, in Europe (at least in the UK and Germany) butter seems to have skyrocketed in price over the last few months, whereas margarine has stayed the same.
Food costs so little of an average western income.
I'd pay a lot more for butter than I do, for all animal products actually, in the hope it would mean better animal welfare.
I think you'd be naive to expect that an increase in the price of butter would be related to increased animal welfare