The Merc ignition is a very good unit, yes parts can be but do not have to be expensive. Why dump a running item before you have an issue, when was the last time any member blew a pack? I an tons of others have been running the Merc stuff for many years with -0- problems, I wanted more spark for my 383 so I swapped out the stock coil for a hot one. I have since picked up an extra pack for $50 and an almost new distributor also for $50, I drag it along on trips. Not knocking after market most of which is good but is it better? Don't ask Maddad about AM stuff he had a baddy!
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.