Think instead about the $2800 you saved over the 1DX.
(I'm still trying to sell my suffering wife on that one. "I didn't spend $4,000. I *saved* $2800." She still doesn't see it that way, but you do, right?)
I have actually rationalized it that way but when the mkIII was announced at $3500 and grip at $350 I was actually saying "only $3000 more and I could have the 1Dx!"
Now I just look at as, "New gear or pay lots of income tax?"