In reply to Richard.

The $250 is much closer to market rate for these than you might imagine if you've searched for them before. I just picked up an early 1900s Macey Company cabinet for under $200 in July: https://boffosocko.com/2024/09/05/acquisition-early-1900s-3-x-5-inch-no-15-card-index-filing-cabinet-with-no-1535-c-i-inserts-from-the-macey-company/

Patience helps a bit, but knowing the market conditions may do you more good if you're looking for one of these: https://boffosocko.com/2023/09/17/market-analysis-of-library-card-catalogs-in-2023/

I've now got enough drawer space for over 200,000 index cards and my cost per drawer averages out at about $12 each.