And for the love of all you hold holy, do not ever put drives bought in the same batch in the RAID at the same time. They tend to fail at the same time. Check those serial numbers first.
That's most unfortunate to hear, because I just bought 10x used Intel X25-E SSDs for my server because SSDLife.exe said they only had 6 months of use, with 99% of their life left & an expected runtime of 10 more years.
With these drives typically around $750/each, it'll be difficult if not impossible to find deals on 8 separate lots of _good_ used drives.
I can only afford them when I see an exceptional deal on eBay, and feel lucky to have found these I just got for $200/each. I strongly doubt I'll be able to afford to implement 1 drive per lot with my server like your warning implies would be a good thing to do.
It seems you'd have to buy them all new at different times of the year to be able to implement such a thing, which I certainly can't afford.
Well, I went with the buy one drive a month from each of my vendors for my RAID.
Use them, but take some precautions. Do real backups and test the backup to make sure it will actually restore. Replace blown drives very quickly. I had a group of C4 SSDs that tanked within 24 hours of each other. I was not amused and thus learned what I need to do in the future.