My NAS (TrueNAS Core) is running with Seagate Exos X16 drives. Those were considerably cheaper than any other drive at the time of purchase (September 2020) here in Germany. From what I gathered  since then, this is often still the case, also in other countries.

But there is one aspect about these drives that needs attention. Being marketed for data center use, they have a very small timeout for parking their heads. So, if an Exos drive is idle for only a very short time, it will move its heads into a parking position. That is a reasonable setting for data centers, where drives are hardly ever idle. But for a small business or home use it is less than ideal.

Fortunately, this setting can be changed and TrueNAS Core, or rather the underlying FreeBSD, has the right program for this already installed. Below you find the command that I am using. You will need to adjust the device, but otherwise you can just run it.

camcontrol epc /dev/??? -c state -d -p Idle_b -s

In terms of the ATA level, this disables the Idle_b power condition and saves it to the drive to survive a reboot. For more details, please check out the extensive man page of the camcontrol command.

In addition I recommend that you configure your system to issue this command on every startup. Under normal conditions that is not necessary. But what if you need to replace a disk drive? If you have a case with hot-swappable drive bays, this will of course not help. In that case I would think about a cron job.