The pet bird rescue we volunteer at saves the molted feathers and sells them on e-bay. Another volunteer cleans all the feathers (make sure there is no contamination), and packages them, lists them and mails them. It's a LOT of work. Last big bunch she sold (likely about 4# of feathers - everything from blue macaws to little bitty orange feathers from a sun conure) - gathered $275 profit. That's taking out all the mailing costs. As she's a volunteer too, she donates her time to clean the feathers, sort them by size, list them, package them, mail them, etc.
Lots of work - yes, some funds - but.....
check the e-bay listings for 'rooster feathers' that'll get you started if this is worth your while.