Check the SMART info on the drives you receive, if they already show signs of failure then return them immediately.
For “reputable” sellers, I typically go with ones who are selling drives in bulk and have a history of more than five minutes with lots of recent good reviews. I took a chance on a good deal for a “new” drive once and received an obviously used drive where the previous person had cut out the SAS bridge (these pins are required to power on some SAS models like what I bought, so the drive was a paperweight). You’ll get some lemons, but I’ve been running mostly used drives on my fileserver for the past twenty years and had reasonably good luck from bulk sellers (and easy replacements when I got a bad drive from one of them).
Oh, you might also check refurbs from Amazon. My current fileserver is running a set of eight 18TB refurbs which were significantly cheaper at the time, but the drive model itself was only a year old so I knew there couldn’t be much wear on what I received. And Amazon has a good return policy.