None of these homes have insulation and their electrical systems are knob and tube, they have plaster walls so you will be playing chase the cracks as long as you own them.

I need a forced hot air furnace for a well insulated 900 square ft row home in the kennsington area of philly

I did have the walls blown in with insulation it did help some but not enough in my opinion. 

Check insulation out there and widows of the great room, you'll have a large flowing space from one side of the house to the other, nice in good weather, just make sure you don't have HVAC issues trying to heat and cool it.Point out to potential buyers how easy it would be to add cover over the deck.

When I replaced mine - I went with exact same brand and tank size but a high efficiency model - measured to make sure same height - Handyman was installing - of course it didn't fit through the door where the old water heater was.High efficiency one had more insulation and about 3 inches wider.  

Did they forget to insulate the house?

so what if u know if there is know and tube or r19 insulation in the attic and not r49.  

He tells you don't worry about insulation because he has a ton of left-over asbestos from the last job.

Particularly important in your part of the country in light of price hikes for heating oil and the high cost to replace.Central air, I'm not sure how many have that up there.Sufficient insulation and the right type.Roof.

I think 30 k is reasonable (again before the drywall, framing and insulation) unless you're going all high end on everything, and I do assume you intend to do some of the work yourslef.