Interview follow up

So, I haven't officially been made an offer yet after I went on that interview not quite a month ago. I thought things might be running slow because of the holidays. Earlier this week, I had given up on the idea that an offer would be made. Perhaps they interviewed someone better, perhaps I overshot their budget. I don't know.
Today I got an email from them though. I got an email saying that things have dramatically slowed down because of the holidays and that they were checking my references. They don't check references unless they are planning on making an offer. Sure, I could "technically" lose the job in the reference check, but that's highly unlikely since I'm the one who gave them the references and I know what each and every one of them is going to say. If they're to that point, I'm as good as hired.
I told this to my wife (the worrier) and she, of course, got worried. She wants to sit down and write down the numbers. We've got to figure out what the bottom line offer is that we can afford to accept. The insurance is ridiculously more expensive at the new place, so if I have to take insurance with them, unless I'm making substantially more at the new job, it won't be worth it. So, it's crunching numbers time.