Serverpartdeals has done me well, drives often come new enough that they still have a decent amount of manufacturers warranty remaining (exos is 5yr) and depending on the drive you buy from them spd will rma a drive for 5 years from purchase (but not always, depends on the listing, read the fine print).

I have gotten 2 bad drives from them out of 18 over 5 years or so. Both bad drives were found almost immediately with basic maintenance steps prior to adding to the array (zeroing out the drives, badblocks) and both were rma’d by seagate within 3-5 days because they were still within the mfr warranty.

If you’re running a gigantic raid array like me (288tb and counting!) it would be wise to recognize that rotational hard drives are doomed and you need a robust backup solution that can handle gigantic amounts of data long term. I have a tape drive for that because I got it cheap at an electronics recycler sold as not working (thankfully it was an easy fix) but this is typically a super expensive route. If you only have like 20tb then you can look into stuff like cloud services, bluray, redundant hard drive, etc. or do like I did in the beginning and just accept that your pirated anime collection might go poof one day lol