To pricey

+1 @johnto...The Nautilus are also awesome.  Many geezers are selling theirs now (think Florida).  I would put the extra $ into the electronics.  The NAD is not up to the abilities of any of the B and W 800 series speakers IMHO.

In terms of resale value, sure.  Deciding whether or not you want to sit with them in a long term commitment however, that's something only you can decide.

In this current climate is better to go with pro speakers and looks for speakers made from wood and not break the bank. Also to build your own speaker is quite easy today and the material is a little expensive but you can make it so much better for a few thousand on a custom speaker is nearly better than a 20000 speaker just saying also diminishing returns is a real thing 

definitely would not pick B&W, I find them a little bright and edgy.

the monitor audio platinum 200 and 300 Gen 2 and gen 3 are much better than anything B&W makes, much more natural sounding and way more three-dimensional.