REI offers the REI Helio Sack 55° Sleeping Bag in Army Cot Green, Asphalt, or Indigo for $39.99. Opt for in-store pickup to avoid the $5.99 shipping charge. That's $20 off list and the lowest price we could find. It measures 72" in length and unfolds into a quilt.
Of note, Long is available for $44.99, also for a savings of $20.