Audioquest Niagara 5000 to use with dual monos

[Rama]

I am contemplating buying the Niagra 5000 together with the tornado C19 power cable. The only thing stopping me is the price tag (£5000). That is a lot of money considering the D440 Pro CI is just around £14K. So my question is how much increment in sound quality do we get and is it worth £5K? I am finding that when listening to classical orchestral pieces the D440 Pro soundstage tends to collapse. My frontend is the Sotm triple set and a Melco N1A, all wired with audio quest diamond cables.