Two sons, early 20s, both have paid £50pw for the last 4 years. I haven't put it up because as they've got older they see to their own food more and sometimes shop and cook for me too.
Both are pretty good at "helping" when asked, they clean the bathroom, do the bins, help in the garden, put the hoover round etc, but they don't do anything regularly. They both work shifts, so that doesn't help.
I used to be a bit of a domestic goddess but for various reasons have lost interest in that and the house isn't looking well cared for. That bothers me, but not enough to do anything about it!
It strikes me that DC probably should pay a bit more, just because that's what happens IRL and if they did I could employ a cleaner. Maybe fortnightly, we can keep on top of bathrooms, hoovering etc it's the "proper" cleaning that doesn't get done.
FWIW I could afford to employ a cleaner without putting the keep up, but feel this is a way to link their contribution to the cost of running the household and they should "feel" the COL itswim. Also, I've never actually spent any of their keep, it's all in a savings account to give back to them when they move out, although they don't know that.
If it is a reasonable idea, how much? Ds1 now earns significantly more than DS2, they were equal when the arrangement started.