I'm in planning for upgrading my NAS. It has a 10Gbps fiber connection, and my main workstation does, as well. My goal is to be able to saturate that with both read and write speed. Timeline is 6 to 8 months out.
Budget in the range of $2000-3000. Currently doing RAID1 on a pair of 18TB disks. I usually want to double that with each upgrade, but there's some leeway on there.
I think my best option is 6 NVMe sticks on RAID6. 8TB sticks would give 32TB of usable space. Not quite double, but close enough.
I would like easy hot swap capabilities. Unfortunately, it looks like the only option for that would be Icydock, and those are expensive. The other way is to go down to SATA drives where relatively cheap 2.5" hot swap bays exist, but a setup that can saturate 10Gbps writes with reasonable redundancy would be even more expensive.
Need a motherboard that has a pair of 16x slots. One needs to be a GPU for Jellyfin transcoding. Also need a 4x slot for a 10Gbps sfp+ NIC. With two NVMe slots on the mobo, this should be workable without going to Threadripper or Epyc chips and such--idle power consumption sucks on those. Totally giving up on hot swap here, though.
There are 8tb NVMe sticks that are priced close to fit in this budget range. I had found one Samsung stick that, according to Amazon price trackers, was around $300 in the recent past (can't seem to find it now). A lot will depend on tariffs, of course.
One surprise is that a Kioxia CD6-R u.3 drive at 15.36TB goes for $1150. 4 drives on RAID10 would be a workable space upgrade. That setup would be out of budget, but not as much as I would have expected. Referb deals or future price movement might put it in range.