Used data center drives are great for a home lab. They're built like tanks for hundreds of thousands of hours of constant operation. Unless you're running a business hosting a bunch of public-facing websites out of your garage, you don't have that kind of workload (and if you are doing that you should just be buying new drives anyway and writing them off as a business expense).

Data center drives get replaced when they hit a ceiling of operating hours, with no actual faults, or if they experience any minor faults (it's a business expense - drives are consumables - data centers have storage rooms of spares sitting around, they just replace them).

Any competent reseller should be able to give you a SMART report, and that should tell you if there are any major issues (generally they don't get resold if there are, nobody will buy them). If the seller won't give you a SMART report then obviously don't buy, they're either a scammer or incompetent.

If your array redundancy is set up properly then there's no reason to be "scared" or trust in "good luck". Assume luck will be bad. Mirror every storage device that has critical/irreplaceable data on it, and have at least one hot standby drive in every pool. Don't bother with complicated striping schemes to try and scrape a little more storage space out of your drives, that's dumb. One-to-one mirroring for every drive. Storage drives are consumables. They will fail, not if but when, even if you only buy new. Learn to read a SMART report. Enjoy quality hardware with no real problems at low prices.