the video quality has improved so much that it would be worth it, even if an old monitor worked.

Higher resolution would be lost on me, since my eyesight is poor. That's why I'd prefer to use an old monitor.

it should work.

My Mac Mini is plugged via HDMI into an inexpensive 27" LED TV. You don't have to get an expensive monitor depending on your intended use - if you're doing hardcore graphics or photography, an actual new monitor with a higher pixel density might be more appropriate for you - unless your old one does what you need.

Again, depending on your use...unless you need the absolute raw power of a Mac Pro, since you're on a desktop you could just get a nicely-equipped iMac and save yourself a lot of space, upgrading the monitor and the CPU simultaneously.

Whoa, there's an iMac Pro now...
3.2GHz 8-core Intel Xeon W processor
Turbo Boost up to 4.2GHz
32GB 2666MHz ECC memory, configurable up to 128GB
1TB SSD storage1
Radeon Pro Vega 56 with 8GB HBM2 memory
10Gb Ethernet
Four Thunderbolt 3 ports
27-inch Retina 5K 5120-by-2880 P3 display
$4,999.00

Mac Pro:
8-Core and Dual GPU
3.0GHz 8-Core Intel Xeon E5 processor
16GB 1866MHz DDR3 ECC memory
Dual AMD FirePro D700 with 6GB GDDR5 VRAM each
256GB PCIe-based SSD1
$3,999.00

iMac
Retina 5K Display
3.8GHz Processor
2TB Storage
3.8GHz quad-core 7th-generation Intel Core i5 processor
Turbo Boost up to 4.2GHz
8GB 2400MHz memory, configurable up to 64GB
2TB Fusion Drive1
Radeon Pro 580 with 8GB video memory
Two Thunderbolt 3 ports
Retina 5K 5120-by-2880 P3 display
$2,299.00

There are other prices and configs, I just grabbed 3 off the website.

Thanks for the suggestions. I probably should have mentioned how I use computers. Besides email and web browsing, I sometimes run mathematical programs which do a lot of arithmetic and deal with large matrices. That's why I want something pretty fast with plenty of memory.

I don't need the snazziest video. Higher resolution would be lost on me, since my eyesight is poor. That's why I'd prefer to use an old monitor.

Mac Pro has Thunderbolt (which is same connector as Mini Display Port) and HDMI. There are readibly available cables and adapters for both.

Apple announced in early 2017 that they will finally release a new model Mac Pro desktop sometime in late 2018. My hope is they'll announce details at the developers' conference, which I believe is in June.

It promises to be far more modular than the 2013 model, more easily upgradeable than the 2012 (your model), and best of all, will have a new Apple monitor available as well.

From what I understand, the new iMac Pro released last month is more powerful than either of the existing Mac Pro desktops, so what they'll release this year should be quite exciting.

Here's a short writeup on what we may be looking forward to later this year:

https://www.macrumors.com/2017/12/15/modular-mac-pro-still-coming/


Last Summer, I went to the Apple store to see about upgrading my 2012 Mac Pro. I was talked out of it, and encouraged instead to invest a small amount to keep my old model running another year, in anticipation of this new release. I figured, if the Apple people were willing to forego selling me a new "old" model, it might be worth the wait to upgrade to something exciting. Don't know what you do with your desktop machine, but as hard as I work mine I'm quite anxious to see where the new iteration will take us.

Please see my response to forgotmylogin (Reply #2) concerning my needs. I just visited an Apple Store. The place was congested, and I couldn't get any service in a reasonable amount of time. Maybe I'll go back in a week or three and see if things have calmed down.

I'm beginning to think that a new model is more valuable because it's new. The iMac Pro is expensive, but it's also new, which means it will be supported longer than either the current iMac or the current Mac Pro, which have been on the market for a few years. Once Apple stops supporting a model, that model becomes nearly worthless. An Apple rep told me their policy is that 5 years is plenty long to keep a computer.

Suppose Apple sells a particular model for 3 years, and then discontinues it. Five years after that, they stop supporting it. Then the effective lifetime of that model, when new, is 8 years. That's what I'm guessing is the case for the iMac Pro.