NC for this, and it will be a bit of a ramble of thoughts.
I don’t think anyone with an ounce of sense would think someone who is looking down the back of the sofa to find enough change to buy a loaf of bread, or having to choose between putting the heating on for an hour or buying something for dinner can be compared to the OP who is wondering whether £350 spare each month is enough.
Clearly, the person in the first scenario is far, far worse off and IMO no one in 21st century Britain should ever be in a position where they can’t buy basic food for themselves and kids and be warm enough. I don’t know what the solution is, and it’s awful. Particularly bad is when families who are entitled to FSM have to get through the long holidays feeding their kids 3 meals a day. Some of these children go properly hungry in the holidays- this shouldn’t be happening.
You could sensibly argue that the only ‘necessities’ a family needs are decent shelter, food, water and enough money for food and enough electric/gas to cook, wash and heat a home comfortably. Sadly this isn’t the case for everyone, and for those people living in poverty without these basic necessities something needs to be done.
On the other end of the scale, you have people who complain about the cost of running second homes or complaining they can’t afford to go skiing this year. Clearly, this is not in any way comparable to those without basic standards of living, and I find it hugely difficult to feel any sympathy there.
BUT there is a middle ground, a bit like the OPs situation. If you have a professional job, work hard, live in an area where living costs are high etc it can be a ‘worry’ to only have £350 a month, there’s no getting away from the fact that it costs money to live, and while you might not be trying to find 50p for bread, you might be trying to find £150 for your car to pass its MOT which you need for work.
I also think people with decent incomes have completely lost sight of what is a necessity and what is a luxury. We have a cleaner. That is a luxury. It doesn’t matter if you and your partner work 70 hour weeks. So do lots of people who can’t afford a cleaner- it’s a luxury. I hear trotted out often ‘but my time with my husband and kids is so precious because I work so hard- I don’t want to spend it cleaning.’ Fine, but do you think nurses, for example, who work long shifts want to spend their time off cleaning? No. But they do.
Of course, if you can afford a cleaner, like we can, great. It saves you having to do it, and you’re providing a job for someone which is good. But please don’t pretend it’s ‘essential’ because it’s really not. Same goes for shopping at Waitrose, putting your kids in pricey holidays clubs if you’re not at work, etc. Those are luxuries. Luxuries that are doing good, actually, but still a luxury.
Today my 2 kids are at a holiday club they wanted to do. I’m not working today. It’s cost me £80 for the two of them. I’ve just been to Waitrose and spent £40 on ‘bits and pieces’ and picked up my click and collect order of a new coffee machine which was £160 as ours broke, followed by having waxing for £45. The postman has just delivered a couple of new bits from a kids’ clothing company from Instagram. ALL of these things are nothing other than luxuries. I’m not saying this to boast. Compared to many people we have a LOT less money than they do. But we (obviously) also have a lot more than many.
I suppose my point in all of this is, it is all relative, of course we should feel much more sympathy for those who are barely making ends meet than those who are contemplating not having another child because £350 spare cash isn’t enough each month. But it’s a sliding scale of ‘problems’ and it’s not a race to the bottom.