Wordfactory, whilst I think you make an excellent point which would be great in an ideal world, we unfortunately don't live in one.
The chances of my DH getting a part-time job in his profession mon-wed (for example), and me get one in mine thur-fri, are non-existant. And even if those jobs could be found, it would be more likely that our hours would overlap in some way &/or we would need help with the school drop off and pick ups, so we'd still only have the equivalent of one ft income coming in, but the additional costs of childcare that we don't have to pay now with me as a SAHM.
What angers me with debates such as this, and comments such as Xenia's above that "it's mostly women giving up work and that's bad", is that I believe woman's equality is supposed to give us a choice. My choice is to stay at home with my dc, but the choice that I have made is belittled by the very people who say that they want women to have choice.
You can't fight for woman's rights, and then when women exercise those rights complain that they're doing it in the wrong way; as surely that makes "feminism" more of a dictatorship than an equalising movement?
And as for the OP, have a chat with your DH, explain how you feel and come to an agreement together as to how the family money is spent - that's what partnership/marriage is all about.