Especially for hard drives. 8TB SAS drives are down to about $45 a piece.
Brand new enterprise-grade 8TB drives are more around $180 new. Meaning as long as you have redundancy (which you should anyway) then you can lose four used drives before it stops being worth it. Not to mention drives get cheaper so if your $45 drive dies 2 years from now you could probably replace it for $35 etc.