Sally, everyone's situation is different and I think in your case you'd be wise to listen to BG. If you find you're only marginally better off then perhaps it's worth putting it to DP that he needs to grow up? Having a kid in CC is more than just the money. There's also the sick factor. I really like the CC centre my DDs go to. Natalie has been going there for nearly 2 years and she's now so fond of the place and the teachers. However, being around that many kids that often means a lot of sickness.
I was fortunate when I went back to work to find a job where my employers were VERY supportive of my family commitments. They didn't have any problems with me taking days off when Natty got sick. And it happened a lot. The new job I've started is slightly more stressful because if one of my kids is sick I can't just ring up and say I'm not coming. I need to arrange for someone to cover me.
It's worth considering.
FWIW, in our case it is a given that I have to work. DH owns his business and we are still paying off a CRAPLOAD of debt. However the repayments come from the business so it looks to the govt that we earn a heck of a lot more than we get in our hands, so unless we find a way to live on DH's small salary alone, I have to work.
On the other hand, it's important to note that I enjoy working. I enjoy getting out of the house and I find that I enjoy my time with the girls that much more than before. My girls are being looked after in CC but also by their grandparents and they're all enjoying that too.
I hope I haven't just confused things more for you. Just wanted to open up a couple more factors than just the cash.
Hope you come to a resolution you are happy with soon, mate. xx