In article .com,
" says...
I've a standalone garage at the side of my house. It was constructed
in 1965 of concrete slabs on a concrete base and has an asbestos cement
roof and is about 5.5m x 3m. The garage leans slightly (a few degrees
to the vertical away from the house) as a result of ground movement
over the years, which has caused the roof to sag and to leak in heavy
rain. Although the roof sheets themselves aren't damaged, the roof is
basically shot and needs replacement.

Two questions:

1. What relatively low cost options do I have for replacing the
existing roof?

I'd have thought that replacing the frame and reusing the existing
sheets would be cheapest.