If the 5 are anything like the 12 I used to have the mids are wired in series so if one is blown neither will work. The fabric is pretty standard, it keeps the fiberglass away from the speaker cones (some drivers have mesh glued to the baskets, it accomplishes a similar thing).
I would not spend that kind of money on another set of 5 just to get the mids and tweets. It's worth sending him a message, explaining your situation, and seeing if you can buy just the spare drivers. Some sellers are quite reasonable.