OP it's not just your school. Loads of schools are asking for more money these days. I agree with just asking upfront for what they require each month and doing it that way.
Our primary school has asked for a lot more money this year than the previous 2 years my DD has attended the school.
We are charged £3 per ticket for any school performances (nativity play, talent show, awards ceremony etc) it used to be £1 per ticket but it was raised to £3 this year.
At parents evening we were strongly encouraged to by our child's artwork for £5 a go. It had been framed in a Poundland frame but £5 is a lot for a piece of artwork made by a child - it's not like I don't have a vast abundance of my child's drawing and paintings at home anyway.
We had several sponsored events through the year done during school time.
Christmas fair, summer fair, Halloween bake sale, easter bake sale. Mother's Day coffee morning, grandparents coffee morning. I'm sure there was more I am forgetting.
Our school are also great at asking for money for trips or specific things and then cancelling them and keeping the money. I paid the school £15 for my daughter to gain access to the website that ties in with her reading book scheme. Not enough parents paid up so they didn't buy the access but no refunds given. 2 school trips cancelled due to bad weather but again the £5 paid to cover the coach costs just vanished. The trips were both cancelled a week I advance so I'm pretty sure the didn't need to pay the coach company anyway.
What else. £1 here and there for ramdom days / dress up events but all at really, really short notice.
Oh and every week from May they have been running a thing where each year takes a turn at selling things to the rest of the school at playtime. So 50p one day for a bag of popcorn or 50p the following week for a fruit smoothie etc. Every week and usually over 2 days per week.
My DDs class also only had 2 rulers between them. So I did go out and buy another 10 to donate to the classroom (they where in the clearance section in Tesco for 15p each - I was just going to buy my DD her own ruler when I spotted them). I think I also donated a box of 100 pencils at some point. Again I saw them on clearance for around £3 and knew they would be useful for the classroom.
What does annoy me is the head teacher applied for grants and spent that money on stupid things. Some crappy benches that are on the grassy but of the playground and subsequently can't be used most of the time as the children aren't allowed on the grass when it's wet. I think the rest of the funds went on wooden boxes that are 'bug hotels' and full of leaves and sticks. I'm sure it was educational learning about bugs but that money could have been spent better. The goal posts on the pitch for example. The paints flaked off and they are rusting away and flaking off all over the place. They look mostly orange now. They need to be fixed up and repainted with a weather proof paint before they become rotted through and not safe to use.