A:Answer $1,200...
On a more serious note, this monitor is bigger and it's WAY less expensive.
On the other hand, the Apple monitor has better speakers, a better camera, better clarity, better colors, better everything really. But you pay for that dearly.
I ended up getting this monitor for general office work. I got an LG 4K Ultrafine for more intense graphics. It's more expensive than the Samsung, but really close to the Apple in display quality. The LG does not have speakers or a camera though. But it was $1,000 than the Apple.
FYI, we transitioned from the 27 inch, iMacs. Our business was exclusively Apple until we got Samsung and LG monitors to go with our new MacBooks.