You don’t have to spend a small fortune to get a TV with quantum dots, the technology that sounds like it should be little more than a marketing gimmick, but in reality delivers a superb picture. Last year Vizio introduced a number of models with quantum dots, and as hands-on CNET reviews have shown, they offer great color and brightness at a midrange price. And right now, Costco is having a humdinger of a sale on the 65-inch M-Series 4K UHD Quantum TV — you can get it for $500 while supplies last. That’s a solid $200 off the regular price. In fact, the cheapest I can find this set on Amazon is $700. It’s such a good deal that I was worried Costco was pulling a fast one on us, putting the M657-G0 on sale. That’s the lower-tier 65-inch M-Series model with somewhat less impressive specs. But no, this is the M658-G1, which has 600 nits of peak output (150% more than the M657-G0) and 90 separate local dimming zones, compared to just 20. Sale or no, this is the one to get.$500 is a surprisingly good deal for this TV. It’s literally priced below the 55-inch version, and has excellent color that rivals what you see much more expensive models like the Samsung Q7. Unfortunately, this isn’t a Roku TV — if only all TVs were Roku — but Vizio’s Smartcast 3.0 isn’t a terrible smart TV solution, and it works with Apple AirPlay 2 and HomeKit which a lot of folks will appreciate. There’s also voice control via Alexa, Siri and Google Assistant, along with four HDMI ports, Ethernet, USB and a slew of other connections. Can you get a better TV? Absolutely — but you’ll pay for the privilege. This 65-inch M-Series, though, was already a good value. $200 cheaper, it’s essentially a steal. This deal ends on May 10, assuming supplies last that long. THE CHEAPSKATE NEWSLETTERAll the latest deals delivered to your inbox. It’s FREE!CNET’s Cheapskate scours the web for great deals on tech products and much more. For the latest deals and updates, follow the Cheapskate on Facebook and Twitter. Find more great buys on the CNET Deals page and check out our CNET Coupons page for the latest promo codes from Best Buy, Walmart, Amazon and more. Questions about the Cheapskate blog? Find the answers on our FAQ page.