Guide Gear ultralight sleeping bag. On sale @ $19.97.
You could get 2 for under $40.00 use them in cold weather in your hammock. I plan on doing this with the 2 I have this weekend. 2 of them weigh only 2lbs 10oz. My NS and Nest will both be in use as underquilts. My nephew using one of them. These things are sweet in warmer weather. Might want to stock up now.