I think $75 was for testing only but maybe I misunderstood, either way Fastlane has them for $25 each. Its interesting that you mention the brass/steel swap. I noticed that mine were brass while I was poking around which would imply they've been changed.
I am curious to hear responses about the in-line filter. I had planned to replace the main filter this weekend as part of the job. I considered doing an in-line filter as well but decided not to for fear of messing with the fuel pressure/flow.
1988 420SEL 170K