Used 2021 GMC Sierra 2500HD for Sale nearSt Catharines, ON

How much does the 2021 GMC Sierra 2500HD cost?

Prices have softened 1.21% compared to this time last year, making it a favourable time to shop this model year.

There are 74 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 — 5/5 is a strong user rating for the 2021 GMC Sierra 2500HD. The overview points to a heavy-duty pickup that leans more upscale than many rivals, with a broader range of trim levels and upscale options than the related Chevrolet Silverado 2500HD. That makes it a fit if you want a work-capable three-quarter-ton truck without giving up comfort or a more premium feel. 35.1% of listings are priced as good or great deals, which gives you some room to shop selectively.

Is the 2021 GMC Sierra 2500HD reliable?

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

The overview also notes that used fourth-generation Sierra 2500HD models can have issues such as check engine lights, infotainment sluggishness, rough or delayed shifts, electrical glitches, MultiPro tailgate faults, and faulty trailer brake controllers. For used buyers, that means reliability can depend heavily on maintenance history and a careful pre-purchase inspection.

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

This is a moderate market for selective buyers, so you can shop with some leverage if you stay patient.

• Deal availability: 35.1% of listings are priced as good or great deals.
• Inventory: There are 74 listings available.
• Price trend: Prices have softened 1.21% compared with last year.

If you find a listing below $56,130 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 $58,100 CAD sits slightly below last year's $58,812 CAD.

That small decline suggests the market has eased a bit, which can help you buy more confidently now. For a future seller, it also means you should expect resale value to depend more on condition, trim, and equipment than on broad market momentum. Well-kept trucks with desirable features should still attract attention, especially in a segment where buyers often compare capability and comfort together.

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:

• 35.1% of listings are priced as good or great deals.
• Price trend: Prices have softened 1.21% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

Consider the 2022 if:

• At $60,440 CAD, the 2022 costs more than the current year's $58,100 CAD average.
• It broadens appeal by blending capability with more everyday comfort and technology.

The bottom line: Choose the 2021 if you want a premium-feeling heavy-duty truck and value a lower average price. If you can stretch your budget and want a newer alternative with broader appeal, the 2022 is the better upgrade path. For price-sensitive buyers, the 2021 remains the smarter buy when you find a well-priced example.

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 October 21, 2026, CarGurus experts' opinions, and generative AI.