The average asking price for a used 2021 GMC Sierra 1500 Double Cab is $26,509, with 83,625 miles on average, across 24 cars for sale at U.S. dealers as of Nov 10, 2026.
Used 2021 GMC Sierra 1500 Double Cabs for sale at U.S. dealers ask $26,509 on average (half ask less than $27,644), across 24 cars. The cars for sale have 83,625 miles on average: one with fewer miles is worth more, and one with more is worth less. To check one car's price against cars of its trim and mileage, enter its VIN in OttoQuest's free Deal Check.
The 12 for sale with a listing date have been listed 83 days on average. A car listed much longer than that, or one whose price has already been cut, usually leaves more room to negotiate.
The 2021 asks $26,509 on average with 83,625 miles; the 2020 asks $23,344 with 98,812 miles.
Used and certified cars for sale at US dealers, each car counted once. Days listed are the dealer’s own days on market where they publish it. Price moves compare the same cars at both ends of the window.
