I am in a similar place to you in some respects. First, you know that real estate has a season and in general it is before school starts. You are getting late in the year. Talk to your realtor and find out how much a sale in a colder time, for e.g. January-March would cost.
If you don't want to sell and move then I don't think you should be paying for the lawyer (and remember I am a lawyer). I was doing ok sitting tight until I decided that I actually want to move. Our house has appreciated a lot and in addition to regular realtor fees and a transfer tax I'd have to pay 25% of proceeds to the IRS if I sell before next summer. Uh, no thanks. Oh yeah, and mine is avoiding the separation contract using every trick in the book (I never saw it, I'll get to it soon, it's not acceptable--but I won't say what exactly I don't like about it).
Therefore, if you don't have any other impediments, and don't want to move, don't push the agreement. Keep in mind though that he could file for the divorce and then you will be paying a lot more to the lawyer.
