I had some joker mechanic try to talk my wife into buying new struts. They wanted $1800 (otrageous, btw), when a Mazda dealer quoted me $1000 for all 4. Anyway, they insisted there was a leak. I took it to 2 dealerships and both said they were fine. I have 110,000km on the car at the moment, so I would assume I should be able to get to 130-140k before I need to replace them. Even this suprised me, however, since I had a pontiac Grand Am GT for 8 years prior with 220,000km on it - even changed the struts, wven though I brought it in several times for evaluation.
Struts are a tricky one. But my guess is the jerk mechanic guy tried to spy oil or water on the struts before having my wife look at them, then tried to tell her it was a leak.
FYI, if anyone is in the Toronto area reading this, it was the Active Green & Ross at Promenade on Dufferin St. that tried to pull this. Avoid all franchises under this name. They're all crooks. No exceptions. Trust me.