A friend pointed me at https://www.govdeals.com (not affiliated) but plugging "government auctions" into Google got me a few hits as well. Not sure about the veracity of all of these sites, but some of them will ship to you.

On the other hand, you're often looking at "Lot of 38 Dell Latitude 5570 Core i7", "These items have been used by students or employees within a professional Community College environment. Items have been maintained, updated, and well kept.", minimum bid $5,800.00

Or something like "(1) Dell Optiplex 780, bad power supply, pickup in-person only, we don't ship" so you'd have to be in the area and interested in swapping a PSU.