sleeping bag

http://www.bobwards.com/products2.cfm?id=74855&attr2=8372&attr1=140393&color_pic=ASH%20GRAY&dept=CAMPING%20GEAR&typ=SLEEPING%20BAGS&subtyp_1=WARM%20WEATHER%20BAGS

A LaFuma Extreme 600 regular length. 1 lb 4 oz. (could remove hood pull cord, etc. and probably get to a pound. $65 right now. I used a long version for from Pearisburg, VA to Mt. Katahdin, ME and still have it. Cheap and plenty for a summer bag.

Here is a great 23oz bag for $150 buy it now
http://www.ebay.com/itm/Marmot-Hydrogen-Sleeping-Bag-regular-black-23-oz-/121064040352?pt=LH_DefaultDomain_0&hash=item1c2ffaa7a0

It did not sell. Maybe it will be re listed. I have one of the black ones and for me it is a true 30 degree bag and I have taken it to the low twenties with bade layer and down sweater. I also use it like quilt in warmer weather. Mine weighs 21 oz it is a great bag. Left zip 6 footer.

REI travel Sack $59, but it is 27 ounces. A liner might fit that criteria though.

A Mountain Hardwear Phantom 45 is 17 ounces, but I doubt you can find one for anywhere near $100 unless it is used.

SOL Escape bivy. Pretty light, pretty cheap. With clothing, I've been comfortable to 50.

< 1 lb and doesn't cost over 100 dollars? That doesn't exist for a real sleeping bag. I think the real question is what temperature range are you looking to be comfortable in? If it's above 60 then you can get away with the SOL Escape bivy. Maybe into the 50's but that's doubtful if you don't have insulation layers on.