I can't make any suggestions for what product to use right now, it's late and I'd have to research a bit, but you basically want something that is going to stay put and isn't going to peel off, I would say that eliminated things like latex paint and points you more in the direction of a thick, sticky product like a silicone sealer.
You might google this for now and see what come sup because I won't be able to do much of anything till after lunch time tomorrow- Friday.
Meanwhile Im sure someone else will suggest something.
There is some of the crappiest advice I have ever read posted in this thread. To the OP, I'd shop around for a competitive price if you are going to have it abated. 3K sounds high, but nobody on here has seen the work area. This stuff is highly friable and doesn't take much to get it airborne. Yes, you could spray it down with amended water, and peel it off, but you absolutely want to be wearing an N95 respirator with P100 cartridges, Tyvek coveralls and disposable gloves. No exceptions and ignore that BS from those who've always done it that way and didn't bother with all that stuff. After you've got it off, you need to dispose of it. Hiding it in the municipal trash is highly illegal and if discovered will net you a fine easily in the 5 digit range or possibly some jail time. After all, if the trash guy comes across it, he'll know where it came from, and point the finger directly at you. As far as the landfill, it doesn't matter what they comingle with it or how they treat it. It only matters that the U.S. EPA has certified the landfill to recieve it. That means that the landfill has shown how they protect the surrounding aquifers, etc. And YOU own it, like it or not, Cradle to Grave. As far as encapsulating, we use Fiberlock or Fosters 32-60 or 32-61. You should look for a rubberized coating. Something brushable. Put on enough coats to completely encapsulate it and lap past the edges by a few inches. RWolff has a good thread about history and health effects under the how to guides.