That is s huge price rise, and the new prices seem very high. I am Chairperson of our school's Wrap around club. We have recently put up prices to account for the increase in minimum wage and rent increase (last year). We we running at a loss, but mainly due to unpaid bills, which are being addressed. Our price increase was around 12% and the new prices are around £4.80 for breakfast club and £8.50 for after school club. These are comparable with other providers in the area, including a nursery which picks up from our school. We also discussed the need for a price rise, and the kind of increase we were considering, at the club AGM last winter, then gave 3 months notice if the new rates.
Your ASC price increase seems very steep and very quick, and the new prices seem very high, although obviously I have no idea how they compare locally to you. The discrepancy between Reception children and existing children is nuts! Ofsted ratios don't exist anymore, so there is no argument that u5s are required to have more supervision.
I'd suggest asking the club for details of how they've worked out their price increases. This might give you a better idea of their costs. It seems very unfair on existing parents to make up the errors if the past, then for future parents to reap the benefits if (!!!!) the prices go down later.
I'd also suggest canvassing other parents' opinions. If the bulk of the club clients truly can no longer afford it and will leave, then it is worth putting this to the club management and seeing if there is a muffle ground.
And look into local CMs quick!