Only having $400 left over (and I'm assuming this is after a pretty austere budget you put together for the other necessities) doesn't jibe with a long-term marriage, a SAHM, your husband's high income (from BOTH jobs, not just the one -- he doesn't get to shelter that 2nd out, it will all come out in the financial disclosures that the court will demand from both of you), and most jurisdictions' "lifestyle to which she and the kids are accustomed" standard.
Sorry, it just doesn't. The CS is the CS, but the SS needs to include a number like $1300 - $1500 per month for a safe, reasonably comfortable shelter for you and his children, preferably in S7's current school district. And frankly, a good bulldog family law atty would see that as an ultimate SETTLING point, not as his or her OPENING point.
The fact that your atty sees your husband's current offer -- if it indeed only frees up $400 for shelter for you and your children -- as "reasonable" is alarming to me.
I know this person is some sort of a family friend, but I seriously think you need to consider shopping for another atty. A BULLDOG. You may have to front the retainer somehow, but your H would very likely have to reimburse you for it as part of any settlement.
Starsky, who's not a lawyer but I did go thru this once and I stayed at a Holiday Inn Express once
