You get a really nice screen with a computer inside for not much more than the price of the screen. The 27 inch screen is beautiful and really large enough that you could live with only one screen if you had to.
Uhm no...
Checking apples page and there is the imac for $1,799, the same panel is used in Dell monitors at the prize of 450$.
Rest of the parts are:
3.2GHz quad-core Intel Core i5
Turbo Boost up to 3.6GHz
8GB (two 4GB) memory
1TB hard drive1
NVIDIA GeForce GT 755M with 1GB video memory
You got 1349$ left to spend, you will get %&$#?@!%&$#?@!%&$#?@!%&$#?@! loads better parts then above junk for 1340$
Gigabyte GA-Z97N-WIFI, mITX wifi board for socket 1150.
Intel Core i7 4790 3,6 GHz, 8MB, CPU.
8GB ram.
120GB Samsung SSD + 1TB 2,5" HDD (and space for 2 more HDD's in the case i picked)
be quiet! SFX Power 2 400W, quiet nice PSU.
Noctua NH-L9i, a low profile awesome CPU cooler.
Geforce 750ti one slot graphics card.
mITX case with single slot GFX card that you can mount on monitor.
Above + monitor costs about same as cheapest iMac and beats the more expensive macs.
So build it all in a mITX case with vesa mount for monitor if space is an issue, loads more performance then iMac, or build a lot cheaper computer at same specs as the iMacs... and buy beer for the money you save.