Been running a used Dell R730xd as my bulk storage box for a while now, and it's probably the single best value purchase in the whole cluster. A few things I wish someone had told me before I started buying used enterprise gear:

• iDRAC Enterprise licensing matters more than people think. Some used listings strip it out or leave it expired, and remote management without it is a real downgrade. Confirm licensing status before you buy, not after.
• Drive caddies are the actual scam. Sellers know this and price accordingly, sometimes the caddies alone cost more than the drive would new. Buy a machine with caddies included or budget for that separately.
• Power draw and noise are not homelab-forum-post numbers, they're datacenter numbers. A 2U server idling can pull more than my entire mini PC cluster combined, and the fans are not quiet, full stop. Plan for where it physically lives before you plan for what you'll run on it.
• Out-of-warranty is fine for storage/backup roles where downtime just means running a resilver, less fine for anything that actually needs to stay up.

Still glad I did it, the R730xd handles ZFS way better than anything in the mini PC tier could, just went in with better expectations the second time around than the first.

(wrote up a fuller checklist version of this at rHomeLab.com if anyone wants the longer version, no pressure, just figured I'd drop it since it's exactly this topic)