I was given a quote for $3,200 for R15 dense cellulose blown insulation into outside walls of my house. The quote includes final patching of holes, so that all I have to do is paint. The holes will be made inside the house into plaster walls. By my calculation, the gross wall area to be insulated is about 900 sq ft. By gross area I mean area that contains windows and a chimney. If I subtract the windows and chimney square footage from the gross area, I am left with about 630 sq ft of net area. I don't have any experience in this field, but the price seems somewhat excessive. It works out to be about $5/sq. ft if I use net area in this calculation. Appreciate any advice on whether this is a reasonable price. By the way I live in the San Francisco Bay Area.