Thing is if you both start them, you likely will want to lose more than 2 stone, for the simple reason you can get to a healthy weight, so why settle for overweight.
you also spend a lot less on food and drink, if you drink alcohol, we still eat the same dinner foods basically just my portions are much smaller, I tend to avoid the carb element and I don’t drink much at all now, where as before I would drink at least two bottles of wine a week, which was 20 quid right there, so the net cost is much lower.
plus you’re only on the higher doses, which cost more for a short period of time, in reality you will maybe do this for six months, to reach whatever target you set, then either come off, or stay on a low maintenance dose , and the lower doses are cheaper.
plus a pill format will be available in the next couple of years latest, which will bring the cost way down,