I've finished the bigger pockets beginners guide and now looking for new material.

I then put $30,000.00 worth of labor and materials into it (besides my sweat equity).

Here the contactors run the flexible yellow pipe which is super easy all be it more costly for materials.

Go online or to Home Depot and look up prices of material for a basic number for estimate costs. 

I sat down with them and demonstrated that they could improve the efficiency of the house by over 50% with an 8 - 12 % increase in materials cost or, postpone finishing the basement and actually spend less.  

My inclination is to do more (10-12) for a couple of reasons; Better pricing on materials and laborI can be on site and so do more oversightIf there is uptake, the PM has 'inventory' optionsLooking for input / thoughts / experiences.

I also make sure all materials are already onsite, and if the contractor picks up something that was not known to be needed.

I would just like to say that it's always refreshing to see a string of first posts from new users praising a company under fire.

That's right around the supply house price here for a low end 2 ton system and that's without a line set, electrical, installation, and any other materials.    

To do this you could cut a piece of rock wool insulation (ether batt or board) to tightly fit into the top of your firebox - I would leave a piece of {bright coloured} string or chain hanging down to remind you the flue is blocked.