What Nick said.

It depends on all kinds of things; slab foundation or crawlspace, interior or exterior walls, attic access or not, etc.

You're really talking about how much TIME you need to buy, and that's just going to vary from one installation - and one installer - to the next.

I learned to do things by actually just being brave and trying. Embrace the concept of "close enough". If it's your house, you can always pay somebody later to fix your screwups. It might be easier than you think.

bibere usque ad hilaritatem