After professionally working as a photographer for 3.5 years I have finally convinced myself that I need a desktop. And boy am I never using my 13" laptop again. This 27" bad boy has retina 5k display (that existed?!) , 24GB memory, 3.5GHz processor (whatever that is but I know it's awesome), the whole works. I'm pretty sure it time travels or something, too. I literally have to turn my head as I move my mouse..the screen size is a bit comical. But it happened to be a better deal, so I'm not complaining.
My point is, if your business is centered around hours of editing, or hours of whatever it is you do, go ahead and treat yo self. You won't regret it.
Cheers to business expenses!