The problem with asbestos is inhaling its fibers. Outdoor use does not present that problem. Asbestos is very common as exterior siding in homes of the era when it was popular. It is very durable, but does need to be painted (while aluminum and vinyl do not require that maintenance). Typically, all other features being equal, you will not find a price differential due to a home having asbestos siding.
If the siding were badly damaged, and removal is recommended, then that requires professionals; and that would then include some charges for proper disposal. However, I believe that you can go over asbestos siding with vinyl or aluminum if you wish. Some people might do that simply to relieve themselves of the painting maintenance.