How about a Bianchi Boron steel? I have a 57 that weighs roughly 1,600 grams. I also have an older Liotto custom steel frame made with Columbus EL/OS that weighs in right at 1,700 grams. Got them both on Ebay, the Bianchi I paid $150, the Liotto I paid $99!
Love them both, just goes to show that like someone said keep your eyes open on ebay, deals can be found!
The Liotto is a custom made frame, pretty rare, it was an ugly teal color when I got it so I repainted it, the Bianchi was in great shape, Celeste in color, can't beat that!
Still though, my favorite bike is my Look KG 281, if you are considering steel for comfort you might think about an older Look frame as well. These were small diameter lugged traditional geometry frames that ride incredibly smooth, nothing at all like modern carbon frames, even more comfortable than steel and are right at 1,500 grams for my 57 frame
Just a thought