I will agree with everyone else. I just found out the hard way. My 30* mummy bag will only compress so much. I can barely get it in the pack and when I do, it darn near takes up half the pack. After going to the Florida Hang and looking at some quilts, I will be going that direction. When I can pack a top and bottom quilt in a sack half the size of my sleeping bag, it's kind of a no brainer. I will save some money by DIYing my own, though. Sorry, there is just not an easy way to go cheap, unless you want to strap your gear on the outside of your pack. Or, carry a 100L 6lb. backpack.
A tree's a tree. How many more do you need to look at? ~ Ronald Reagan