The Western Mountaineering bags can't be beat. I used my Megalite in 24 degrees and was warm, it's a 30 or 35 degree bag.
Santa brought me a WM Versalite 10 degree bag for Christmas.
I looked but could not find a sale on WM bags. They sell so good I was told they never have a sale. EVERY sales person I have talked to at a high dollar outdoor store or online store has a WM bag, usually two.
Go ahead, pull the trigger!