longevity of good speakers


i am somewhat new at the audiophile game and i am looking for some advice on speakers. NOT SUGGESTIONS. my question is in buying a high caliber speaker like the verity ovations on the used market, with average play, approx. 20 hrs./week, how long can they be expected to play at their top form? in other words, if i buy a six year old set of good speakers, how long could i realistically expect them to give me great satisfaction?
128x128mpmll
I need to get some of those magic crystals for sure!!And a smart clock and a few call-in tweeks and some stones and a few of those twisted tuning forks,etc.
I forgot to mention I keep all of my speakers in special pyramid structures with crystals hanging inside.
One of my pairs of speakers is 30yrs old and sounds wonderful. The other is 13-14yrs old and sounds wonderful too.
I can beat 30 years. My mother still uses my first set of speakers, I bought second hand in about 1970. They are Leak mini sandwiches and still sound pretty good, a bit soft of course. She is nearly deaf anyway, so that's alright.
One of my pairs of speakers is Celestion SL 700s from the 1980s. The Zu website claims a life expectancy for their Essence speakers of "Lifetime on cabinet, 40 years plus on Zu260FRD/G4, 15 years on ribbon foil (serviceable)" and for their new Soul Superfly speakers of "100 years plus cabinet, and drivers, including the Zu260FRD/G4 HO; even in direct sunlight."