I asked this same question recently on the USPS Reddit page if they jacked their rates up, and they just all thought I was crazy and had no idea what I was talking about. I couldn't give proof because it would take several hours to gather all the data. I just forgot about the discussion topic and didn't get any farther than that. I noticed that the shipping quotes are in the $80+ range now for vacuums too.
A lot of the vacuums I bought on eBay, everyone always shipped them upright. They were just normal people selling an old vacuum and not collectors or anything, so they probably didn't know how to remove the handles. I don't think I've ever gotten a vacuum yet that was that well broken-down into all of its individual parts.