If these tubes were indeed "steel" tubes they would be a lot cheaper. But I doubt there is much steel in them at all. They are made on ceramic, Aluminum, silver, tungston, and no doubt a host of other rare metals. And there is a brand new 8877 on ebay right now for 550. You just have to know how to shop. Just like I found a 572b exactly the same as the Taylor from RF parts for 39 bucks each.
Rich
Rich