The one name I've heard most often for buying feathers in bulk is Rainbow Feather Co. I don't have a link handy, but I'm sure you can search it up easily. Unfortunately, my handout from CostumeCon's wing panel only has links to armature and harness designs, no other feather companies. But they are out there. I know there's more than one, I hear about wings all the time on cosplay.com.
Thing is...$200 is pretty damn good for a full-sized set of wings. If you think you can just buy a set that size for less than that, you're crazy. Hell, I'm not sure you can even make a set for that little. I suppose it depends on how dense you want the feathers to be, the fewer you have to buy the cheaper. Making them static - that is, non working - will also cut costs on the harness. But you won't get a full-sized set of feathered wings for *considerably* less than $200 if you make versus buy.