No one mentioned "big-box places" but dirty feeders, yeah, I can see that being a problem. Thanks!
Even a local shop can be an issue, but you need to be careful wherever you get them from. Buyer beware... Prior to purchasing, look in the feeder bin and what do you see. Ask them what day they get feeder deliveries and then look at the bins the previous day. Are they clean or dirty?
Regardless, you can generally get better pricing from a supplier directly. Hopefully they are doing things right on their end.