As a matter of perspective, here are the particulars of my project:
My house was built in 1917, is a balloon framed 1.5 story bungalow built on a crawlspace. I am doing my entire project myself and have had some help on the roofing from my brother-in-law. I am reshingling the roof (done), replacing gas piping (done), rewiring the second floor and kitchen (rough inspection tommorrow), I've gutted the second floor to access removing inadequate and possibly moldy cellulose as well as birds nests and to remove knob and tube wiring.
This last part is key. I did all of the removal of lath and plaster first, and before that I took an EPA certified renovator course. As a homeowner working on my own home, I am exempt from the requirements relating to lead paint dust work practices. But I wanted to learn the practices and follow them to the best of my ability to minimize exposure for my children so I could get the part of the project done and cleaned out before we moved into the house.
Anybody that does a whole house insulation project as a contractor is very likely to have to follow these practices, and their price will probably reflect that.
My costs for the project would include the dumpster rental, replacement drywall, drywall finishing, paint, and insulation material.
For insulation material costs, I am using Johns Mansville fiberglass batts and my total for the material is under $800, which I know because I made my initial purchase in November and I bought $600 of material before a rebate deadline and I had figured I wouldn't be buying enough to be over $800, they had a rebate that was $100 rebate for $400, $150 rebate for $600 or $200 rebate for $800. So I got a $150 rebate for my purchase of $600, plus by the time I'm done I figure I need another $125, plus my first floor walls I will blow in cellulose for which I'll need 14 bags at $9 per bag, so including rebates it comes to $700 in insulation material.
Attic airflow is part of the project as well, and this is important to ensuring the insulation will work proper and not be degraded by humidity, so there's around $150 in baffles going in for that. The drywall I'm putting in to recover where I gutted the lath and plaster is around $200, and that will make it a little over a $1000 project to insulate the house.
If you are considering taking this on yourself, let me recommend this website:
It has a lot of very good information about how to do it right and I'd highly recommend it.
Of all the projects I'm taking on, I'd say insulating is one that I'd definitely say can be handled without a lot of DIY experience, although I haven't yet done blowing in insulation to say first-hand how easy that is.
Let me also add this: we're moved in now. I insulated the ceiling including the sloped ceiling part of the second floor, but not the knee walls. It's been adequate to keep the rooms warm enough for comfort, and our heat bills have been around $200. Finishing the insulation of the walls will definitely improve that, I just have had to hold off until the electrical rough inspection is done and I can't cover my new wires until after that.