A boiler north of 25 years in age has only scrap value. If it has a stainless steel heat exchanger that's easy to pull, that value might buy you more than a 6-pack. As mixed-metals a scrap yard won't give you much for it though- it has to be separated.
Hopefully you did the heat load analysis (from either fuel-use against heating degree-days or a standard Manual-J or I=B=R type heat loss tool) to right-size whatever you are replacing it with? Almost all boilers in New England seem to be 3x oversized, often more, as if people were expecting -150F weather to settle in or something. Oversizing a boiler has both efficiency & up-front cost consequences, but all too often a hit in comfort to boot.