My bulk storage box is a used Dell R730xd, and after going through the process I've got a short list of things I wish I'd known going in:

• Check iDRAC Enterprise licensing before buying, not after. A lot of used listings have it stripped or expired, and losing real remote management is a bigger downgrade than it sounds like on paper.
• Drive caddies are where sellers actually make their margin. Sometimes a handful of caddies costs more than the drives you're putting in them. Either buy fully populated or budget for caddies as their own line item.
• Idle power draw and fan noise are datacenter numbers, not homelab numbers. This thing alone can pull more than my whole mini PC cluster combined, and it is loud. Figure out where it physically lives before you figure out what runs on it.
• Being out of warranty is a fine tradeoff for a storage/backup role (worst case is a resilver), a worse one for anything that actually needs uptime.

Worth it in the end, ZFS on this thing runs circles around anything in the mini-PC tier, just went in more clear-eyed the second time than the first.

I put together a longer checklist version of this over at rHomeLab.com if anyone's curious (linking since it's directly on-topic, not trying to spam), but the short version above covers the big ones.

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)