I would never invest in cheap decoys. Even if they decoy birds the paint will chip and they won't last as long. I have bigfoot decoys that I have been using for 10 years now and they still kill birds. A good decent decoy will work as good as others and will last a long time.
On blue bird days, the better the decoy the better you'll do.
Location, weather, concealment, set up and knowing when and how to call are all more important factors than what the brand of your decoys are.