A treadle feeder can definitely help with reducing feed loss to waste and pests. There are other "no waste" feeders that can also be used. Which is right for you will depend on your flock (ie if you intend to raise chicks in the flock they will not have enough weight to activate the treadle step to open the feeder), your budget, etc.
Are you losing feed to billing of feed into the bedding/onto the ground? Are you losing feed to pests such as wild birds, squirrels, etc? Are you not so much losing feed as just seeing more consumption than you had expected?
Other ways to reduce the feed bill that are not associated with reducing feed waste are fermenting the feed, feeding a higher quality feed that requires less total feed to provide the same, or better, nutrition, etc.