We have one DS, then boy/girl twins. DH is high earner but it's still unbelievable the amount of money we get through each month.
We don't live extravagantly. But we live. No abroad holidays since DT were born, the logistics while they are this small is too much.
Our food bill is huge. It includes all nappies/toiletries/food/cleaning stuff, but we spend about £1000 a month on 2 adults, teen DS and DT.
Nursery, they get their 30 free hours, and we get tax free childcare. In order to do this full year, the 30free hours becomes 22 free hours a week, so the 8 weekly extra plus consumables costs us £646 a month.
I have to say, you don't sound particularly cut out to be a sahm if you struggle to make a meal on the two days a week you have them at home, if you'd then be doing this 5 days a week with another child in tow. The financial benefits of being sahm aren't just the childcare savings. It's the savings by being able to source cheaper food and cook from scratch. I go to separate shops for our meat to our veg and a different one for cleaning stuff etc. I get bundles of clothes from FB, weed out what I want to keep and then list the rest of the bundle on eBay and generally make a profit. I get loads second hand, like furniture that I do up (set of sunbleached Neptune chairs for £280, which I've dyed over the course of a month and look brand new) and can search for and go and pick up toys for next to nothing.
I really enjoy all my bargain hunting, and it means we can afford to live well, as opposed to scrape by, but it the amount I save doing all that easily balances out the nursery bill, you can make big savings when you have the time to plan and do so.
We could probably cut back and live more frugally, and it would be good to have more savings, but it's our choice not too, because we want to have quality of life, not just exist. If DH wasn't earning well, it would be quite a miserable life, with constant money worries. It's one thing to live cost effectively but knowing there's a fall back in emergency, but quite another to be living from pay packet to pay packet and praying the boiler/car/washing machine doesn't give up this month because the electric bill was higher than expected.