The basic challenge here is that the new boiler weighs 400 pounds, and the old boiler weighed even more. Plus, of course, the radiator system is full of water that had to be drained out, and there was pipe-cutting and pipe-supporting involved, and so forth. A big hassle indeed.
Did I happen to mention that the former boiler was only manufactured between 1950 and 1957? It was showing its age, too. It is now in a big pile of cast iron and asbestos in the garage; we'll probably have to break up the heat exchanger with a sledgehammer to get the garbagemen to take it away.
Nevertheless, it is clear that the way to get a furnace replaced cheaply is to have a close relative who's an HVAC engineer. Les managed to get the furnace at wholesale by going in with a former co-worker, he managed to pick up the expansion tank for free, and he's not charging us for his labor. We are getting one heck of a deal here.