Cheap, Light, Compact Sleeping Bag Options?

I agree with Eric. There have been lots of criticisms of the EN13537 ratings and testing system, but IMHO they are the most objective criteria we currently have. It's discouraging that they are often misused here in the US. I keep seeing the "extreme" number (the temp at which you hopefully won't be dead of hypothermia in the morning) used to rate bags (I don't think that number should be there at all), and seeing the "lower limit" (for men/warm sleepers) number used to rate women-specific bags.

While I love my Western Mountaineering sleeping bag, it's quite discouraging to have to go to UK websites to find their EN13537 ratings! They sell their bags in Europe, so they have to have them tested–why aren't the results on the WM website? What are they trying to hide?

For a good layperson's guide to these ratings, read this blog entry from Philip at SectionHiker:
http://sectionhiker.com/deciphering-en13537-sleeping-bag-temperature-ratings/

Hi-larious, how the discussion can turn so needlessly esoteric. (Please, count to ten realize your "points" might be "true" even though they actually "don't matter at all")

SHORT ANSWER, without the BS, is still "Kelty Cosmic Down 20" in the shortest length that fits the hiker. There's a thorough review of the item on this website. It is, simply, not an esoteric product but rather one that fits the OP's criteria with laser-like precision.

Now, let me paste in some statistics from something… :)

If you have time (a couple hours) and access to a sewing machine, you could sew a zipperless, hoodless sleeping bag or quilt with synthetic insulation for about $50

3 yds 2.5 oz Climashield APEX from Thru-hiker @ $10/yd
5 yds 1.1 oz nylon ripstop from DIY Gear Supply @ $3.20/yd

Plenty warm to 45 degrees and easy to sew. My first ever sewing project was an APEX quilt; it's really not difficult to sew something this simple; it's just cutting some big rectangles, pinning them down, and then simple straight line stitches.

If you don't have access to a sewing machine, you're out of luck in this direction though.