Fish don't care if its high quality or cheap.They just want it to look edible.Dollar stores and walmart's have lots of tying materials in the craft and sewing departments.I buy bead chain for cealing fans at walmart or lowes and make eyes with them.You may be suprised what you can find in your local Goodwill or Salvation Army stores.I have found items with fur collars,tons of feathers and plenty of foam items.
Cheap tied flies may not last as long but they're inexpensive to replace.
I flyfish for panfish most of the time and they're not to picky.For saltwater you may need to use the more expensive stuff.