FTTT - good luck with the job application!
I'm certainly not intending to get stuck into the SAHM vs. Working Mum argument - both sides have their merits.
But what I would say is this. In my experience, there comes a point when you need to earn a certain amount to pay for the childcare. Unless the childcare is reasonably priced, you will need to earn quite a lot to make it worth while financially. The more you get paid, the more the employer wants from you - be it in responsibility, or hours etc - and the harder it is to juggle. So yes there are financial benefits from earning a good salary - of course there are - but as a consequence of being paid a fortune, for example, I was expected to travel all over the world at the drop of a hat (not as glamorous as it sounds believe me), to have my mobile phone on 24/7, to work as a minimum 12 hours a day, to take work home, to work all through my 'holidays' etc etc etc.
I guess my point is that although on paper there may be an obvious tipping point, there are sometimes hidden costs which might alter the equation.
I hope this helps you. Ultimately, it is a decision that only you and your DH can make. Whatever decision you make, believe in yourself and your ability to make the right decision. Never mind anyone else's view!
Good luck