I don't mention prices due to forum rules, but that is the correct street price and I paid a little bit less. And yes, that is cheap!
From yout reading, you are correct. It can be used as a hardware controller because it is a hardware controller, and as such, because it is a USB MIDI device(no external MIDI ports, it's a "dead end" product), you can use it WITH MyDMX to trigger scenes and control channels.
But, let me clarify a few things. First off, this controller is very soft. I configured mine using a profile to emulate a JLCooper CS102, because I use ProTools MPowered on the same machine I use MyDMX on, and ProTools MPowered requires I configure the nanoKontrol this way for compatibility. But, for your applications, this is trivial. It's only worth mentioning that the unit itself is highly configurable.
Now, once you have the controller hooked up, the controller itself is NOT learning anything. You have to tell MyDMX what MIDI things to respond to. In USER mode, you can assign note values to scenes for triggering, which is where the 72 buttons come in handy on the NanoKontrol. In the EDIT mode, this is where you can assign the faders and knobs to DMX channels. It needs to be mentioned that you need to set those same DMX channels into either HTP or LTP(on a per channel basis, find out which mode works best for you and yes, you can mix and match) if you intend to or need to be able to do over-rides or have tweaking abilities. For example, you can make a scene with movers doing circles, but leave your gobo and gobo spin channels in HTP mode, and that way you can choose your gobos on the fly as well as if they spin.
You of course still need MyDMX running the whole time. The laptop would be doing the vast majority of the work, while you would have some ability to play on the fly. In the case of the show I am designing, I am choosing to leave control over the high-tech FX to the DJ's, with marked faders showing channels for the Mystic, Verigo, Sunray II, "scanner bank" and "small dancers", so they can play with those as they feel fit. The rest of the show will simply loop and hopefully get the job done.
I look at the nanoKONTROL as a vital tool to help me maintain some degree of human control should it become necessary. Since I am not good at color mixing on the fly, I leave that alone. I like the color schemes of my light show, but I may feel the need to add something by adding gobos or gobo spin to my movers, or add the hi-tech FX as needed(if I even use them). The rest, I more or less leave alone.
That's how I look at it. Even so, MyDMX has saved me time in programming since I have assigned multiple DMX channels to the same fader on the nanoKONTROL. For example, I typically use my 8 64 LED Pros as one large bank of lights, but I want the lights to remain on their own sets of channels for better control, and as such I can have MyDMX do things like rainbow chases. But, let's say I am programming my shows and dialing in colors, I assigned all like channels on those fixtures to a single fader on my nanoKontrol. So, all red channels are on one fader, green on another, blue on another.... Works great.
Sound triggering is not possible with MyDMX. You'd have to use MIDI to emulate sound triggering, but it wouldn't be true sound triggering and not from the standpoint that MIDI is not sound, but from the view that a sound type trigger would work like a drum trigger and that drum trigger would only ever output one note from the brain unit.