I buy my canned air at Walmart and I get a 3 pack for about $4.99, a years worth to say the least.
Rocky, your local Walmart must be a lot less costly than mine, I thought I got a good deal for 4 cans (one free) at $11.88. A single can is almost the price for the three you stated above.
Those 4 cans will last 4-6 months, because when I get down to two, will purchase 4 more.
I go through so many due to working on other's computers, plus am always upgrading something in one or more of mine, even if newer SATA-3 cables. IMO, it's hogwash that computers that shipped with SATA-1 HDD's, that the old OEM cables are just as capable of high performance SATA-3 usage. Every now & then will acquire an older PC or notebook, if either, will install a SSD (& fresh install the OS). Ran tests with the old & new cables, the new always produces faster benchmarks.
Just like HDMI, some articles insists there's 'no difference' between a cable designed for HDMI (1.3 spec) and 2.0b. These folks must think we all live within a cave. Same with Displayport cables, only certified DP 1.2 cables (Accell being one of the leaders) can push the difference in bandwidth.
OK, need to get back on track here, though was emphasizing a point. Whenever I open one of my computers, will always use that opportunity to blow out the case, as all electronics are a magnet for dust, not just computers, think of what the inside of some early Smart TV's looks like by now. And others that's ran for 10 years or longer & never opened. Even a PC monitor attracts dust, can be seen in the grooves that allows for cooling.
No matter how it's done, as long as it's not a setup that blows moisture in, and can be adjusted to a low flow rate, it's best to dust a computer no less than once per year, even if in what one feels to be a 'clean' environment. This is exactly why refurbished HDD's (such as 'White Label' found on eBay) aren't worth fooling with, I ordered one as a replacement for an IDE HDD & performed worse than the 10 year old one.
This is because only the OEM's has the resources to properly recertify HDD's, the room has to be 25x cleaner than a surgical room. Not a speck of dust, moisture, anything can land on the heads during reassembly, otherwise it's going to be returned again within days to 2-3 months at best, any contamination will cause the drive to fail. It can't be done in a garage or basement & be expected to last any amount of time.
Note that while blowing air throughout the computer, especially with notebooks, be sure to secure the fan to prevent free spinning, this can damage the bearings of the fan. Also, it's only meant to be spinning in a certain direction. If nothing else, a broom straw through the fan blades through (usually) a hole in the bottom & taped on the exterior, will hold it in place. It's good to use a Q-Tip to gently clean the fan blades prior to blowing out. On a desktop, it's much easier to clean the blades, though some CPU fans can also be small. I'll blow out my heatsinks every 6 months, whether or not it's needed, and reinstall thermal paste every couple of years, even on a GPU, the pastes used on these are often gobbed on (way too much), only a half of a rice grain or Arctic Silver 5 (aka 'AC5') are needed on many GPU's. I just cleaned up one 2 days ago that was 4 years old, while the paste was still very soft, it was enough to use for at least 3 more cards, if using AC5 (after blowing out the card really well), will use the 'half rice grain' method, then use a plastic tool to spread it into a light glaze.
Then run a few 'burn in' or 'torture' tests to help it cure faster, after that, normal usage will finish the job.
Animal, I've placed that item on my Amazon wish list, the device will pay for itself over & over again!