Lafuma 800 40* bag at REI
I'm not much of a salesman but summer is rolling around and some folks may be in a similar boat as myself.
I have had this same bag for 2 seasons now and am outfitting my younger brothers for a weekend in the woods.
$38 and change for a bag that has taken me down to 35* in my ground dweller days (granted I was shivering, but with only a summer weight top and bottom and below the temp range of the bag, it was my own fault. I'd say 50 would be a comfort range for this bag as my testing over the last 2 seasons has illustrated).
For anyone that is looking for a huuuge bang for their summer buck - this bag is it.
(They occasionally have regulars in stock, they are usually around $50, but he is 6'1'' anyways so this actually is advantageous)