The Lifespan of an LP?

If you question hearing your record anew vs much wear, consider getting a needle that tracks higher or lower in the grove than the previous wear pattern.  (Keeping in mind that tracking lower in the groove necessitates extremely clean vinyl)

Vinyl is tough stuff.  Consider that a diamond stylus incurs wear (i.e., has to be replaced) against vinyl, and not the other way around.  Vinyl flexes, gives up its detail, and then returns to normal after a diamond is dragged through its trench.

Your great grandchildren will be listening to them. You can’t wear out a record. 

Okay, Whart is 100% correct.  Inna is wrong!   Sorry, the vinyl record, if of good quality or near 100% virgin vinyl, is an elastic medium.  Once played, it requires about 24 hour rest period prior to returning to it's original shape.  Hence, I have LPs that I have played 100+ times which sound as good (or better with upgraded room and electronics) as long as I treat the record with care. 

I have 28,500 LPs.  The last three collections I purchased include120 LPs from a guy who only bought 25¢ to $1 LPs, often damaged, always used, 2500 LPs from a guy who took great care of his LPs but also often purchased used/abused LPs, and 800 LPs from a guy (major record/CD producer) who had 200,000+ LPs but didn't discern condition (sometimes perfect, sometimes dreadful, mostly used).  So, buying collections or parts thereof are not so full proof.   Oh yes 3 years ago I purchased an opera & classical LP collection of 1200 LPs which were in mint condition.  The owner was fastidious and did not play them very often.  That's the quality of a collection everyone wants.

Also, cleanliness of the stylus, condition of the stylus and turntable set up is paramount to maintaining one's collection.  

Usually after about 20 plays or so I start hearing some small pops. They are still negligible. Maybe after 50 or so, the play noise is readily noticeable, and that’s the time for ultrasonic cleaning. After cleaning, it gets a little bit better, but the small pops do not completely go away, which means the damage is permanently done. However, I would still rate those records as Mint- or VG+++.

The damage is mostly due to badly setup cartridges, old/damaged cartridges, and playing dirty/damaged records. So, if your cartridge set up is near perfect and if you clean records each time you play with needles in good condition, the record will remain in VG+ condition after hundreds of play.