Hi, I have a 14 year old house that has oil heating. We had an annnual tune up done last month. Repair man told me that the smoke box (think he also called it a 'flue collector' ?) needs to be replaced. Then he called me the next day to tell me that the company that made the heater (Ducane) does not make that part anymore and it would have to be custom made to the tune of $400+. Does this sound reasonable?