Flyingwil, you should be able to get a high-quality, lightweight three-season bag in that price range from one of the better makers such as Marmot or Mountain Hardwear. If you never plan to carry it except in a car, a $50 item from Cabella's will serve you just as well, and you get the deer and ducks on the flannel lining thrown in free.
I've reviewed, at a guess, a couple hundred sleeping bags in the last decade, and reached a few conclusions. For lightweight bags, down is best, period. No synthetic insulation has yet come close in weight savings, compression, and most of all durability. A good down bag will outlast three or four synthetic bags at least, making it the most economical choice in the long run. The only theoretical advantage synthetic bags cling to is superiority when the insulation gets wet. But really, how many people have you known who got their sleeping bags soaked in the field? When I sea kayak I put my down sleeping bag inside two dry bags and forget about it. Condensation and body vapor are not factors if you buy a bag with a waterproof/breathable shell.
With the increasing availability of prime Eastern European goose down in recent years, loft ratings have skyrocketed. 800-fill down is now common; however, anything over 600 from a reputable maker indicates good down.
For three-season bags I don't personally like tight mummy shapes unless I'm really going featherweight. A semi-mummy or rectangular bag is much more comfortable. Likewise, a full-length zipper is a good idea.
Depending on your height and size, I might have a bag or two around that would suit you. Email me if you like.