I have no issue with buying used NAS/Enterprise drives (particularly when I will be using them in RAID arrays, or with other methods of redundancy) , but for personal use it would only be where something like a CrystalDiskInfo screenshot is provided.
I look at both the Power On Hours, and the Power On Count, and will generally look at drives with lower power on counts, and power on hours that are in the 1-2 year range.
High power on count (i.e. in the 100's) isn't great for drives as it puts more stress on the mechanicals (in the same way that spin up/spin down power saving can also contribute to earlier failure)
Equally excessively high power on hours increases the risk of failure due to the amount of use.
It's also worth ruling out drives based on age as well, as even a low power on count/power on hours drive can be a risk, as old drives not used potentially can have issues with moving parts seizing, or just being badly treated if left on a shelf as a spare etc.