Shocks
Le Mans Master
Joined: Jun 2002
Posts: 6,426
Likes: 3,611
From: Commerce Texas
Race Director
Joined: Apr 2017
Posts: 13,602
Likes: 12,864
From: Virginia
Second, how do you want to define "'last"? It can be defined as until they start leaking fluid or how much fluid leak is acceptable (most all shocks will leak a little fluid-film) or until they totally cease to function for the purpose they are designed to function.
I owned a chain of auto parts store for 16 years and some customers changed their shocks/struts around 50,000 miles others not until they totally failed at a 100,000>200,000 miles or more.
Here's a document that GM uses to determine what shock leak is acceptable or not for warranty replacement purposes.
Melting Slicks
Joined: Aug 2018
Posts: 2,013
Likes: 1,590
From: Clermont, Florida
As far as cost goes 4 base OEM shocks are around $375 online and install yourself. My guess at a dealer would be $800 installed. Add a little more if you upgrade to Z51 shocks for a stiffer ride.
Administrator
Joined: Mar 2001
Posts: 368,132
Likes: 24,733
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
I would say you should be able to get at least 75K miles out of a set of shocks in normal driving.
Race Director
Joined: Mar 2001
Posts: 19,952
Likes: 6,754
From: Bonneville Salt Flats
If not terminally leaking computer-controlled ones, they can last indefinitely. Just check them once in a while. Mine have been on my C5 for 20-years this month and are still quite adequate, still better than on any of my many other vehicles, apart from my C7. All the best. 
