You can find microfiber lens-cleaning cloths on the web for less than $2, or pay $6 for a "Canon" microfiber cloth (or buy at a retail camera store for $15-20). Are all such cloths pretty much the same, or is there a reason to pay more?
I can't speak to the microfiber cloths specifically, but often the Canon/Nikon-branded small accessories like this really are nothing special. For example, I had some Canon lens cleaning fluid and it was pretty much crap. Stuff like this isn't actually made by them anyway - it's 3rd parties that license the brands.
I've not had great experience with microfiber cloths. For now, I'm trying disposable papers (Pec Pads). A lot of people like Kimwipes. (Oh, and I had some Canon lens paper that was pretty much crap too.)
Microfiber clothes are built specially so that it doesn't leave any scratch while cleaning your sensitive lens/s. If I were you, I wouldn't take any risk which involves leaving a stubborn scratch in my lens or even a minor one, almost invisible to human eyes. These things are mostly cheap, and you can use any one of them available, not necessarily it has to be from your camera manufacturer. I use one which I got with my Sony VAIO for cleaning the LCD screen. Its better if you can ask a few friends what they use before buying one.
And just so you know, for cleaning dust, its recommended to use blowers in general.