Even if your net take home is negative after childcare costs, I've got to say, yes work does pay.

One, in sanity - heartily sick after one year's maternity leave of seeing only other new mums, with the same old broken record on what goes in one end and comes out the other and the trouble it causes in between. What a blessed relief to hand over the little darlings to be someone else's problem for the day and seek adult conversation and a bit of mental stimulation. You'll find you're far more pleased to see them when you collect in the evening.

Two, also good for the children to get a mix of carers - one day they will have to go to school on their own. Get 'em used to the routine of separation young and they will be cool on the first day and won't embarrass you in playground.

Three, unless you plan to remain out of the employment market indefinitely, an extended career break isn't generally good for your promotion prospects/earnings potential and you could find that your industry has moved on, leaving you behind, so in terms of lifetime earnings, paying for childcare could earn dividends further down the line.

Oh, and if you're used to paying extortionate nursery fees, private school fees don't come as such a shock to the system! (brace for impact..)