I took my gear to the local retail store to get a pack. My sleeping bag in a 33liter compression sack took up a 3rd of the 85 liter pack. The Guy there put a down bag in a stuff sack and it compressed to half the size of my synthetic bag.

I am wondering, if I go to a top quilt and button quilt, down filled, how much space will it take up?

Also what is the price comparison from a DIY top quilt to a store bought one? Thanks for all the help.