I would get a recertified enterprise drive from Server Part Deals. Drives in the 12-18TB range currently have the best price per TB. Be sure to get a SATA drive if it's going in a desktop.
I've purchased refurb drives from both them and GoHardDrive.com. So far I'm 5/5 for a mix of Exos and HGST Ultrastar drives working perfectly out of the box.
Anytime these drives pop up on Slickdeals, the thread is full of 3 types of people: People who have never bought a refurb/recert drive but insist they are all going to burn your house down, people who have bought several with no issue, and people who have received a failing drive that the seller promptly replaced.
In my experience, Seagate exos are only "loud/clicky" when under HEAVY write loads. Mostly they're pretty quiet with a very low drone at worst. In any decent case it'll be pretty negligible. With headphones on doubly so.
This is my experience. I had them on my desk in a test bay to make sure they were all good to go and the only time I notice them is when they're doing a lot of read/write movements. While they idle they're quiet. So it depends on your use case, where the drive physically is, and what the drive is attached to. If it's mounted with nice rubber dampers or something you might never hear them. If they're mounted up to a loose chunk of metal they might rattle and drive you nuts.
IMO, yes. HDDs are always going to be a bit noisy, but the consumer grades keep it fairly classy. The couple of HGST drives I got from ServerPartDeals are noisy in the "grating" way. The volume is similar but the noise is not in the normal pleasant range. I am only fine with it because my server is in another room.
I recently got some Toshibas and they were loud. They also presented with a seek error pre-fail after a few days (all three of them). That propably adds to the volume, but the seagate and wds I switched to just have some clicking noises. Not too bad.
Was the drive scanned for errors before installing it? I’ve been running 2x8TB drives for about 1.5 years. If a drive fails, it is better to find out earlier while they are within warranty.