I use surge protectors on stuff I don't want to replace ;)
At home, DW and I have a small den, with our 3 computers and two printers plus the cablemodem, router, etc. I put surge suppressors on everything, although if it's raining/thundering we turn them off. Once or twice we haven't. We did have a lightning strike close to the house that did hit our wiring and lost power. The surge suppressor had "insurance" on it and we were able to collect; her $1000 computer was a total loss. Of course the point is that it didn't protect against the lightning strike - so it would have been on our house insurance instead.