Upgrading your iMac`s memory yourself is cheaper than going through Apple
(iMore iPhone)

While Apple charges a premium for memory (RAM) upgrades on all of its computers, one of the best aspects of the iMac line is that RAM is user-upgradeable — at least on the 27-inch model. This means that you can skip Apple`s in-house, expensive RAM upgrades and efficiently perform much more cost-effective ones yourself. Our best memory for Mac choices serves up several excellent third-party RAM upgrades that you can get right now. For later expansion OWC 16GB DDR4 RAM (Single stick) Staff Favorite This single-stick kit gives you plenty of room to expand to 32GB or even 64GB in the future should you want to. $75 at B&H 128GB for less Timetec Hynix 128GB DDR4 RAM This set of four 32GB RAM sticks offers the maximum amount of memory you can put into a Mac for just a fraction of the price of Apple`s upgrade option. Perfect for high-end video work and development or opening just a ton of Chrome tabs. $476 at Amazon Top tier for most consumers OWC 32GB DDR4 RAM A kit ...