Really the problem with Nano wasn't the price so much, though that obviously is important, but the fact that there are very few cases where the size of the Nano is a definite advantage. In fact, for most itx cases you can fit in even a Fury (!) but more importantly also a 980 ti or 390, etc. So the size advantage is.. almost moot. It's cool to look at, sure, but not that important ultimately. Now how does the smaller size translate into temps, airflow & noise? Answer is, not very well either. The Nano is quite loud (and whiny) and temps aren't much better than other cards nor the air flow either. And as far as performance goes, while it performs well it's significantly slower than a 980 ti or even a Fury X (which has problems itself because hybrid solutions for mini-itx have their own obvious downside - fitting it the fan), while something like a 390 Nitro can generally do within ~10% of it in most scenarios in mini-itx for the most popular cases. So with the nano you get neither great value nor great performance nor silence.
So besides the coolness factor why pay so much for a Nano? Answer, not much reason at all, hence why so few sell.
