That's my point: used cMP buyers do not buy cMPs instead of new Tubes, they buy them because Apple won't sell them a minitower in the $1200-$2000 range (they used to).
It's not as if a quad core i7 rig will take the place of an 18 core beast for truly professional work in video, audio, and science.
what you say is partially true. there should be a lower cost option. for two years, Apple has offered the current Mac Mini. Max that out with i7, 16GB RAM, a 512GB SSD, keyboard and mouse: $1800. still dual core, still integrated graphics. do that with the Mac Pro, I'll go 6 core, D700, 512 SSD and figuring 3rd party RAM: approaching $5500. looking at that, I can only even recommend and iMac, and only since 2015 when they got rid of that low gamut screen and under-powered graphics. all of Apple's offerings are thermally constrained. none of them are suited for use as a server (too under powered (Mini) or having to pay for unneeded graphics cards (Mac Pro) plus the cost of rigging them to work in a rack).
that Mac Mini is incapable of being a graphics workstation (though a quad core 2015 update with user serviceable RAM could very well have, entry level). the abilities of that Mac Pro can be eclipsed by a well modded cMP for far less.
I was in charge of the hardware for a mid-sized design and video production shop from 2010 into 2015. I bought some new Mac Pros at the start but once I dug further in I realized Apple was overcharging for then. Some of the 2010 releases still used last gen CPUs. the 2012 update made some adjustments based on Intel updates and price drops that had happened in 2011 but with no new graphics cards. why would I buy a new machine when I could start updating entry level 4,1s (now all over eBay) and for $1500 less, end up with the same machine or better. And what did I most want from the update that finally dropped at the end of 2013? 8 RAM slots for that quad channel memory controller. something that Dell, HP, Lenovo, etc. already had in their mid-tier Xeon workstations. 128GB of RAM was the goal. Instead we went backwards. I had no Thunderbolt peripherals. even with a very capable and extensive server infrastructure I still had a need for multiple internal volumes. TBs worth. Apple's insane upcharge for the 1TB upgrade was not the answer. the choice was, keep working with the cMP or spend hundreds of thousands of dollars for an incremental update. and almost 3 years later, nothing about that proposition has changed. yes, I can now, through 3rd party vendors, put 128GB in the trash can, for significantly more than it costs to do that in a dual proc cMP.
and as you mentioned, "18 core beasts". the needs of 3D/CG work (Max, Maya, Nuke...) has been out of the reach of Apple for some time now, especially when you want to build a render farm*. so yeah, I've been expecting the wholesale industry changeover to Windows for some time now. but people (myself included) are keeping those old Mac Pros (and even a few trash cans) on their desks, waiting and hoping. I guess we all find out by years end whether Apple cares as much as we do. it's a shame no journalist, columnist, blogger... that gets access to Apple's executive team will ask that one simple question re. the Mac Pro, what do they expect people to do?
* before anyone returns with, you can build a Mac Pro render farm... yes. but it's a terrible waste of space and money. and only
very recently has any sort of final rendering taken advantage of GPU processing (and still a limited case tool), and then usually with Nvidia hardware. so the included GPUs are just a waste of money and electricity. the last render system I set up put 160 real cores and 512GB of RAM (across 8 systems) in 4U of rack space. just over $50K custom built. to get that much potential with Mac Pros, using the 12 core and racking it. At least double the cost and 7 times the real estate. no thanks.
