With the 2yo it should be easy to get things that don’t cost, I’m a huge fan of homebargins toys. I got my 4yo DD a big unicorn thing, I think it’s called ritzy roller for £6, last year I bought her cheap Princess dolls for 50p & 99p from the clearance bins, the boxes were slightly damaged.
You could probably get lots in home bargains for the older 2 as well. One of my DDs favourite gifts a couple of years ago was a bloody ruler with a calculator in it, cost me 89p. I also discovered a pencil case that was the exact same as her ridiculously expensive smiggle pencil case for like £2.99… ive just bought all mine raindeer onesies for £6 each.
Definitely keep up with the charity shops, I’ve managed to get some good Christmas gifts in them over the years. Last year my then make up obsessed 6yo got a make up case for £4 (one of those big metal cases) I put lots of bits of make up, glitter, brushes in it, all cheaply bought from home bargains.
Also look at free gifting sites in your area. At times when we’ve struggled they have been a godsend. Things I’ve got from them, football boots, toddler trampoline, go cart, piano, tv with DVD player, roller blades, dining table the week before Xmas last year…. A friend of mine who manages a care home was looking for baby dolls for some of the residents, I asked in one of our local groups and lots of people offered lots of good quality dolls. Never be afraid to ask if you need help, you can always pay it forward when you can. Where I was living last year there were a lot of families hit hard, lots of them had never needed to ask for help before and were embarrassed. There were community groups set up to make sure all the families from the local schools didn’t miss out. See if there is anything in your area, even if it’s you go along to a free Santa event they might be hosting for the kids it’s something.
Also, you could dress things up to look more than what they are. Aldi crisp box’s are fantastic. I occasionally grab an empty one just for my DDs to sit in and watch telly lol the love playing in them, I keep saying one year I’m going to wrap the boxes up to look like giant gifts and fill it with gifts, put lots of paper in it and the DDs can go hunting through them for gifts.