PC hardware just keeps getting cheaper and faster. Now that so many people have been working from home the deficiencies of home PCs are becoming apparent. I’ll give Australian prices and URLs in this post, but I think that similar prices will be available everywhere that people read my blog.
From MSY (parts list PDF )  120G SATA SSDs are under $50 each. 120G is more than enough for a basic workstation, so you are looking at $42 or so for fast quiet storage or $84 or so for the same with RAID-1. Being quiet is a significant luxury feature and it’s also useful if you are going to be in video conferences.
For more serious storage NVMe starts at around $100 per unit, I think that $124 for a 500G Crucial NVMe is the best low end option (paying $95 for a 250G Kingston device doesn’t seem like enough savings to be worth it). So that’s $248 for 500G of very fast RAID-1 storage. There’s a Samsung 2TB NVMe device for $349 which is good if you need more storage, it’s interesting to note that this is significantly cheaper than the Samsung 2TB SSD which costs $455. I wonder if SATA SSD devices will go away in the future, it might end up being SATA for slow/cheap spinning media and M.2 NVMe for solid state storage. The SATA SSD devices are only good for use in older systems that don’t have M.2 sockets on the motherboard.
It seems that most new motherboards have one M.2 socket on the motherboard with NVMe support, and presumably support for booting from NVMe. But dual M.2 sockets is rare and the price difference is significantly greater than the cost of a PCIe M.2 card to support NVMe which is $14. So for NVMe RAID-1 it seems that the best option is a motherboard with a single NVMe socket (starting at $89 for a AM4 socket motherboard – the current standard for AMD CPUs) and a PCIe M.2 card.
One thing to note about NVMe is that different drivers are required. On Linux this means means building a new initrd before the migration (or afterwards when booted from a recovery image) and on Windows probably means a fresh install from special installation media with NVMe drivers.
All the AM4 motherboards seem to have RADEON Vega graphics built in which is capable of 4K resolution at a stated refresh of around 24Hz. The ones that give detail about the interfaces say that they have HDMI 1.4 which means a maximum of 30Hz at 4K resolution if you have the color encoding that suits text (IE for use other than just video). I covered this issue in detail in my blog post about DisplayPort and 4K resolution . So a basic AM4 motherboard won’t give great 4K display support, but it will probably be good for a cheap start.
$89 for motherboard, $124 for 500G NVMe, $344 for a Ryzen 5 3600 CPU (not the cheapest AM4 but in the middle range and good value for money), and $99 for 16G of RAM (DDR4 RAM is cheaper than DDR3 RAM) gives the core of a very decent system for $656 (assuming you have a working system to upgrade and peripherals to go with it).
Currently Kogan has 4K resolution monitors starting at $329 . They probably won’t be the greatest monitors but my experience of a past cheap 4K monitor from Kogan was that it is quite OK. Samsung 4K monitors started at about $400 last time I could check (Kogan currently has no stock of them and doesn’t display the price), I’d pay an extra $70 for Samsung, but the Kogan branded product is probably good enough for most people. So you are looking at under $1000 for a new system with fast CPU, DDR4 RAM, NVMe storage, and a 4K monitor if you already have the case, PSU, keyboard, mouse, etc.
It seems quite likely that the 4K video hardware on a cheap AM4 motherboard won’t be that great for games and it will definitely be lacking for watching TV documentaries. Whether such deficiencies are worth spending money on a PCIe video card (starting at $50 for a low end card but costing significantly more for 3D gaming at 4K resolution) is a matter of opinion. I probably wouldn’t have spent extra for a PCIe video card if I had 4K video on the motherboard. Not only does using built in video save money it means one less fan running (less background noise) and probably less electricity use too.
I currently have a workstation with 2*500G SATA SSDs in a RAID-1 array, 16G of RAM, and a i5-2500 CPU (just under 1/4 the speed of the Ryzen 5 3600). If I had hard drives then I would definitely buy a new system right now. But as I have SSDs that work nicely (quiet and fast enough for most things) and almost all machines I personally use have SSDs (so I can’t get a benefit from moving my current SSDs to another system) I would just get CPU, motherboard, and RAM. So the question is whether to spend $532 for more than 4* the CPU performance. At the moment I’ll wait because I’ll probably get a free system with DDR4 RAM in the near future, while it probably won’t be as fast as a Ryzen 5 3600, it should be at least twice as fast as what I currently have.