Used 2021 GMC Sierra 2500HD for Sale near Niagara Falls, ON

How much does the 2021 GMC Sierra 2500HD cost?

Prices have softened 4.45% compared to this time last year, making it a favourable time to shop this model year.

There are 79 listings available, which gives you a modest amount of inventory to compare before you decide.

Is the 2021 GMC Sierra 2500HD a good car?

Yes — the 5/5 user rating suggests you’re looking at a truck that resonates strongly with shoppers who want a heavy-duty pickup with a more upscale feel. The overview points to a broader trim spread than the related Silverado 2500HD, plus Denali and Denali Ultimate versions that lean more luxurious, so you can shop from work-focused to premium-oriented configurations. It also offers a wide range of comfort and technology features, which helps if you want capability without giving up everyday convenience.

With 30.4% of listings marked as good or great deals, you have a decent chance of finding a competitively priced example.

Is the 2021 GMC Sierra 2500HD reliable?

Owners rate it 5/5, a strong signal of long-term satisfaction.

The overview also shows that this truck is built around familiar heavy-duty hardware and a broad set of trims and configurations, which can be appealing if you want a proven, flexible setup. At the same time, reported issues include check engine lights, infotainment sluggishness, rough or delayed shifts, electrical glitches, MultiPro tailgate flaws, and faulty trailer brake controllers, so a careful pre-purchase inspection matters.

For used buyers, the main long-term ownership risk is ending up with a truck that needs expensive repairs or repeated troubleshooting if those known problem areas show up.

Is now a good time to buy a used 2021 GMC Sierra 2500HD?

This looks like a moderate, selective buyer’s market, so you can shop patiently and still find worthwhile options.

• Deal availability: 30.4% of listings are priced as good or great deals.
• Inventory: There are 79 listings available.
• Price trend: Prices have softened 4.45% compared with last year.

If you find a listing below $56,244 CAD, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2021 GMC Sierra 2500HD's resale value?

The current average of $57,429 CAD sits slightly below last year's $60,106 CAD.

That softer pricing can help you buy more carefully now, but it also suggests future sellers may need to be realistic when it’s time to list. If the market stays balanced, a well-kept truck with desirable equipment should still attract attention, especially if it’s configured with the trims and features shoppers want.

Vehicles with strong owner satisfaction ratings, like this model year's 5/5, tend to retain buyer demand, which supports resale value over time.

Should I buy a 2021 GMC Sierra 2500HD or consider a different year?

If you're weighing the 2021 against nearby model years, here's how to think about it:

Choose the 2021 if:

• 30.4% of listings are priced as good or great deals.
• Price trend: Prices have softened 4.45% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

Consider the 2022 if:

• At $60,560 CAD, the 2022 costs more than the current year's $57,429 CAD average.
• It broadens the truck’s appeal with stronger emphasis on off-road ability, infotainment, trailering technology, and safety.

The bottom line: Choose the 2021 if you want a more affordable heavy-duty Sierra with strong owner satisfaction and a wide trim range. If you’re willing to spend more for a newer model with a broader feature focus, the 2022 is the better secondary path; price-sensitive buyers should stay with the 2021 and target well-priced listings.

How does the 2021 GMC Sierra 2500HD compare to the 2021 Ford F-250 Super Duty?

Read our full side-by-side expert comparison here.

These recommendations are based on CarGurus' proprietary market data from November 4, 2026, CarGurus experts' opinions, and generative AI.