new oil furnace should cost
1 Oil furnace cost is roughly $2,500 to $5,000 installed, but similar to gas furnace prices, itâs not unheard of to spend $10,000+. 2  The average propane furnace cost is $3,000 to $6,000 installed. 3  Again, though, costs could reach or exceed $10,000. The typical gas furnace cost is $3,000 to $6,000 installed, although higher efficiency models and/or complex installations could push the cost up to $7,500 to $10,000 or more. 2  Oil furnace cost is roughly $2,500 to $5,000 installed, but similar to gas furnace prices, itâs not unheard of to spend $10,000+.