Sibling comment mentioned Govdeals, which is a place I'll look sometimes if I can find something near me or they're willing to ship.
You can look on Craigslist as well, especially if you live in a large metro area (I live in NYC so it's easy to find lots of corporate surplus). Companies will often need to upgrade all their infra and liquidate their equipment. My printer is a giant nearly 20 year old HP office thing that I got for $30 + $100 for the Uber back home from an office that did a full IT renewal.
