I carry zero degree rated Walmart / Coleman bags in my vehicles. Have slept in one down to around 20F quite comfortably. They are for getting stuck overnight in the vehicle, impromptu car camping, and for use in bundling up a roadside accident or hypothermia victim. Don't mind if they get bloody or stained.
Not expensive, too bulky to backpack, heavy for their comfort rating, but functionally warm for car camping. Easy to replace if vehicle is broken into.
Mentally add a minimum of 20 degrees to whatever advertised comfort rating is on a big box store China bag.
I own several expensive premium sleeping bags, but I don't discount cheap bags as long as they are utilized within their limits.
E6Jarhead: You'll probably find that your new bags are warmer than your old .mil one (which version I have slept in many years ago). Sounds like you got a good deal for the money. Try 'em out backyard and confirm your comfort level before you go someplace where the temps could kill you. In a pinch, with two bags, you could always unzip one and throw it over the other quilt-style. 7 lbs of insulation (both bags together) is going to keep you warm regardless!