I am a consumer. I had too little RAM with 16GB so I upgraded to 32GB. As for too much money, I only wish I had that problem.
Your condescension aside, I'm a consumer who knows quite well how computers work and I needed, and bought, 32GB of RAM.
I run one Linux VM full time, to which I allot just 1GB for memory and very occasionally run a Windows 8.1 VM which is alloted 4GB. Aside from that I just run a LOT of apps. I don't want to worry about what I have open. When I was at 16GB, the memory pressure would often get quite high, and the system slowed down, writing to swap memory.
Thankfully, I no longer have this problem with 32GB and I am very glad I made the purchase.
I'm not saying every user needs 32GB of RAM. I'm sharing my own experiences (without hurling lame personal attacks) and not presuming that my own situation is the correct one for everyone.
For those actually looking for advice on this issue, open up Activity Monitor and click on the Memory tab. If the Memory Pressure is rising out of the green level or you see a large number designated to Swap Used: you could do with more RAM.
If it is in the green and the swap is small or zero then you are OK with the amount of RAM you have installed.
If you're buying a new iMac then the decision is a bit harder. I think 8GB is a good choice for most users to start with. I went with 16GB because I wanted the 2 x 8GB sticks of stock Apple RAM so that I could just add another 2 x 8GB of third party RAM for the max 32GB and not have any RAM to replace or sell. Also with RAM prices as high as they were then (and now), it wasn't that much more for the Apple 16GB then the third party.
Finally, for those buying the 21.5" iMac I absolutely recommend going for the max 16GB since it is not (easily) user-replaceable. You need to practically disassemble the entire logic board to get at the RAM slots. You wouldn't even want to attempt this on a Mac under warranty.
I'm sorry if you took what I said as personal attacks. I was making general statements, and they were in no way directed at you. I think we may have different definitions of what a consumer is. My definition of a consumer is somebody who watches movies, does word processing, and browses the web.
If you want to have 3 VM's open at the same time running consumer programs, then go ahead and knock yourself out. 16GB should still be enough for that, and in my personal opinion, an SSD would serve you much better than 32GB of RAM.
When I made the generalization between consumers and professionals, it was a generalization. I was saying that people either know what they are doing and can make the right purchases, or people do not know what they are doing. I'm not saying that you fall in the second category. I was just saying that there are many people out there who don't realize that the spinning platter HDD causes a bottleneck.
I overreacted, and I apologize for that. I was not attacking you personally, and when I used the word "people" I really meant people in general. I absolutely agree that RAM can be invaluable, and sometimes it can be the most important upgrade. For a consumer who is not using Photoshop and VM's on a daily basis, I think an SSD is a much better purchase. I personally believe that in most consumer scenarios, RAM is used to coverup the underlying problem of an outdated HDD. This is not always the case, but I think in most cases this is true.
I just gave my 2010 MBA with 2GB of RAM to my grandmother a few months ago because her old computer died. It was still running strong, and I didn't have any issue watching movies, looking at my photos, browsing the web, or playing video games (Portal 2, League of Legends). I just got a 2014 MBA, and the only noticeable differences are the battery life and the backlit keyboard. If my old computer had an HDD, I would have probably thrown it away years ago. With an SSD, I was able to do all that stuff on the latest version of Mavericks.
TL;DR: RAM can be invaluable, I wholeheartedly believe that. There is a point though where it is cheaper (and even faster!) to have RAM page onto the SSD than it is to avoid paging onto an HDD. I really don't know how you use more than 16GB of RAM without some sort of "professional" software running, but to each his own.
Best, and apologies for being rude,
Matt