My plumber is recommending a 120 BTU Burnham PVG-5 with an 85+ AFUE for my 3000 sq ft colonial on Long Island, NY. The natural gas company is supplying it at a reasonable cost. However, my research shows the Burnham Revolutuion II has an AFUE at 90+ and their CHG unit has a 94. The cost of those units are 1600 and 1800 dollars more respectively than the standard PVG. From any of your experience, is it worth the extra bucks for a higher AFUE which would equal savings on fuel? The plumber suggests it would take better than ten years to recoup the cost difference at todays natural gas prices. My question is, am I agonizing over this too much and should go with my plumbers suggestion or, in the long run, will the 5+ better AFUE make a difference? Thanks!