Basically, if you go the official route you WILL pay a lot for an i Mac 5K.
However, there is another way to get more bang for your buck.
Not every Mac has every option, of course, but for the ones that do, it''s worth asking — which upgrades are worth the price?
I bought the base model i Mac 5K a couple of years ago and recently upgraded the memory myself, using the You Tube tutorial below. I picked up 32GB of memory from them for 6, which is a HUGE saving on what it would have cost me had I chosen to get this installed by Apple prior to purchase.
Starting with the 2015 i Mac update, Apple solders the RAM to the logic board for the 21.5-inch models, making user RAM upgrades practically impossible (Update: i Fixit has discovered that the RAM and CPU in the 2017 21.5-inch i Mac are once again socketed, making RAM upgrades possible, but difficult and warranty-voiding).
This means that if you think you’ll need more RAM than the stock 8GB, either now or in the future, you’ll need to shell out the cash up front to ensure that your new i Mac remains viable in the years to come. While each year we fear that Apple will take away the ability for user upgrades, the 2017 i Macs thankfully retain the four user accessible RAM slots.
Here’s the info that RAM upgraders need to know for the 2017 i Mac and the upcoming i Mac Pro.
First, like the older models, those purchasing the 21.5-inch i Mac are out of luck when it comes to user RAM upgrades.