I theorize that it's because they're server grade equipment, and the used market for server gear is not that large. Most established businesses don't want to risk buying something that straight up doesn't work or will fail later, even at a 50-75% cost benefit. It just isn't worth the time spent dealing with it.

If you're a one person startup, then you do what you have to do to survive. Eventually you get to the point where free stuff actually costs you more than just paying for it in the first place.