What Apple iMac To Buy: New 27-Inch With Retina 5K Display ($1,999) vs. iMac 27-Inch ($1,799) Planning to get a new iMac but your budget won’t allow it? Apple unveils a cheap new 27-inch iMac with Retina 5K display. Here’s how it stacks up with the older 27-inch iMacs. by Nicole Arce