Before you say you can't afford them, check around first. Campor has a 20 degree down bag that's lower quality down, but it's less than 200. Also sometimes you can find secondhand down bags of better brands in forums (Feathered Friends, Nunatuk, Western Mountaineering, Montbell).

I got around the "expensive down bag" issue by getting a quilt. I would use my Jacks R Better 3 season quilts on the ground if I ever had to, they work wonderful with my hammock and were 220-260 (got one on sale). I also figured in that synthetic will not last as long as down. I fully expect to be using these quilts even after I'm too decrepit to backpack, because I also have used them on my bed. (I don't care that they're bright green, they're light and warm and I don't care for heavy bedcovers. )