I know many people on here already recommended SPD as a source for fair priced disks. I just wanted to add my $.02 after a recent experience with a failed drive I'd purchased a few months ago.
A week ago I woke up to a TrueNas notification that a drive was faulted. I did some troubleshooting and wasn't able to recover any kind of connection to the drive. Plugging it in to a external adapter resulted in what sounded like a rock tumbler, so clearly it was beyond rescue. I started a RMA with SPD, and went back to work; expecting a few hours delay before hearing anything back. Later I realized I'd missed their almost immediate reply to the RMA request. I explained there was no way provide smart test results, and attached a video of my new rock tumbler. In short order the RMA# was provided. I shipped the faulted drive, and didn't think much of it. The drive was delivered yesterday and my replacement shipped this morning.
Long story short, big kudos to ServerPartDeals for what is unprecedented customer service in the modern world; and to all the unsure shoppers, spend your money with SPD.