While the FF/WM bags are the best of the best (I prefer FF), if you are on a tight budget you really should try to Stoic Somnus 30. Stoic is Backcountry.com's house brand, and while some of their stuff is hit and miss; I really like the sleeping bag.
850+ fill down, mine weighs around 1 lb. 4 oz. Brand name shell fabric... and the best thing about it is the price. I paid $125. If you look around long enough you should find it around that price.
FF is a great bag, and if you really take good care of your gear, FF bags will last a long time. But, if you are under a tight budget constraint, check out the stoic somnus.