Painting the cooler fully black adds 2-3 degrees.
its been tested and they are effectively same (within margin of error) and actual differences are more often than not fan related (as all fans have an accepted variance from what they are listed at)
The D15 is old, so way cheaper than its starting price,
original msrp when it debuted in 2014: $99.90 (if u doubt it check their sites article of when they 1st announced it) same as it is today.
because something is "old" doesnt mean it gets cheaper. a top of the line product has no reason to depreciate in value until it has a replacement.
its extremely big and ugly as sin.
can get it in black. (and ur saying the mastercooler one with the ugly top plate is better? well everyone does have different tastes i guess)
So no, the pricing is fine for the Coolermaster
noctua has the best mounting hardware in industry. (everyone should adopt that as its simple)
afaik best warranty in the industry (they ship you for free a new bracket if a new socket comes out as well)
some of (not the best ever) the best fans in the industry.
is it fine for a high end cooler? sure. However noctua's perks make it best choice if you dont mind getting nh-d15.