Before you do anything, check with what you'd be replacing it with. So many products have asbestos in them, it is amazing! Paint, insulation, siding, plastering materials, adhesives, roofing materials, I can go on and on.
I'd be willing to bet money that most of the posters here have asbestos in their homes, in one form or another, without even realizing it.
For me, I don't think I'd worry too much about the exterior siding. I might insist on fresh paint (check for that asbestos, again!) before the purchase, but you could do that yourselves (and, in checking on the paints/stains you'd use, feel secure knowing it was asbestos-free).
The guy from our abatement service was telling me about how he removed the ceilings from his older home (because of a large positive asbestos reading). He replaced them with a different texture that was "spread" on (looked like thick plaster/stucco). After the job was completed, just for his own personal interest, he tested the new texture. Yup, it tested positive for asbestos!! So did the paint he used to redecorate and the new shingles on his roof!!
He told me that many of the building products that originate in CANADA still have a lot of asbestos in them. Canada doesn't regulate this as much as the US! Not a big environmental surprise to me, but still..........
Did an independent lab do the asbestos testing for you, or was it a business that also sells the removal service? I'd have it tested, again, by an indie lab, if that's the case. They have nothing to gain, financially, with the results.
We just had asbestos abatement completed on the inside of my Dad's house. It had that 1970's blown-on "popcorn" ceiling texture. It covered approx. 1,000 sq. feet and was just over $4,000. Another abatement service would have been over $4,500, and still another $4,900. So, it does pay to get more than one estimate before committing to a service.
Make sure any asbestos service provides you with a "paper trail" explaining exactly where the removed product(s) end up (not just the regular landfill)!
Also, contact your local Dept. of Ecology (or EPA) office and ask them about the companies you are considering using, to make sure they are reputable!!
Best of luck!