Attic Furnace How Much Should I Be Paying To Buy And Install A Horizontal 90% Efficiency, 80-100K BTU Furnace In My Attic?

How much should I be paying to buy and install a horizontal 90% efficiency, 80-100K BTU furnace in my attic? - attic furnace

The device must be installed in the attic. I was quoted $ 8000 for 90.000 to 100.000 BTU horizontal 90-92% efficiency and installation unit. How do I compare prices without having to go to 2 hours for the sale of each appointment on time?
Thank you in advance for your help.