Unikely that all 3 coils have failed all at one time. That leaves the power pack, stator and timer base. They are all expensive to replace. The least cost path is through some diagnosis. If you are not averse to troubleshooting, the factory service manual is a good place to start. Also this website: cdielectronics.com
I wouldn't replace parts by rationalizing percentages-it can get pretty expensive. The documents referred to show how to actually test for failed/condemned parts.
