Written 21 Aug 2026. Specs from the maker pages linked below. Prices from those stores. I haven't used these.

When used office gear is a gift

Start with gear you already have. An old laptop, or a retired OptiPlex from Marketplace, is the first lab. A cheap used switch can wait until you have something running. It is a trap if it was built for a cold data-center aisle.

If you have not read it yet, start at start with what you already have. You don't need to spend money to begin. This note is for the next used box, after that old PC is already on.

Buy used

• An old laptop or a Marketplace OptiPlex / EliteDesk / office mini PC. That is the first computer. See start with what you already have.
• Fanless or near-fanless switches you can identify by exact SKU. A used UniFi Lite or a known 8-port 2.5G is fine if the seller shows the board, not a blurry rack selfie.
• Small Synology 2-bays that still get DSM updates. Check the model against Synology's current update list before you click.
• DAC cables, optics, and patch. Commodity. Buy used all day.

Skip used

• 1U/2U Dell / HP / Lenovo servers from 2016–2019 as a first lab. Idle is often 80–150W. At $0.15/kWh that is $100–200 a year to host what an N100 does on 12W.
• Big Cisco Catalyst with default fans. The ports are lovely. The noise is not. You will move it to the garage and then you will not use it.
• Mystery “10G card” listings with no chipset. You want an Intel X710 / XXV710 or a known Mellanox SKU, not “works great.”

Before you click buy

If you can't name the idle watts, the NIC chipset, and where the next firmware lives, it isn't a bargain. It's a project. Projects are fine. They just aren't the default buy.