I have a late 2013 27" iMac, 3.2GHz, 24 GB RAM, 1 TB storage. My two main concerns are 1) to increase storage for images mostly (not interested in cloud storage, and would like to avoid more external drives), and 2) the computer has been absolutely trouble-free, but I wonder how long the hard drive will keep going. In looking at newer (or refurbished) 27" iMacs, they are a lot more expensive, and many have SSDs that are only the same as or less than my hard drive. I started to wonder if I could just upgrade the hard drive? (I gather it can be done, and I would take it to a pro). I'd be grateful for any insights about whether this is a workable idea, and how cost-effective it would be.