Hi OP. I understand where you're coming from.
There isn't an easy answer.
You have to ask yourself just how much this bothers you, and weigh it up.
Would you really go no contact with them if it wasn't for your children? Are they truly that unpleasant or do they have any redeeming qualities? You said they were good parents when you were young so do you not have some love for them somewhere in you?
Do they care about your children/ have any kind of positive connection with them?
There's a lot between parents being a bit annoying/ wanting to parent again/ having views and opinions that are different to yours (my parents are like this) - and actually wanting to cut them out of your life.
You decide where the line is, but my parents would have to do something pretty bad for me to actually go no contact, even though I find them difficult on many levels.
Are there any examples of the sort of thing they actually do that you find problematic?
If you really do feel strongly that they are awful and you would be no contact if not for your children, then you have a couple of choices really:
1)Swallow it, deny your own feelings (pretty toxic for your own health tbh), "play nice" in order to get the money.
2) Try to limit contact whilst not actually cutting them out - call them a bit less, be a bit more distant, but be there when they really need you. I'd guess you'll still have to bite your tongue a lot.
3) Cut contact anyway. You say you don't need the money, it would be nice to have for your children, but is it actually worth it?
I'd probably try to go for something like number 2, but it would not be a very pleasant way to live.