Oh Yoder! You are so quick to react, pass judgement, and to display your immense propensity for always finding the good deal!
I'd guess you're referring to the Rackmaster bag on Amazon?
Look closely! THIS bag has a picture or a really BIG buck on it! While I am sure the habitat you manage holds many such bucks, I'd bet the Durana you found for only $5 a pound didn't have any pictures on it? As an added bonus, this "Amazon" bag is coated and reinforced to protect it from heavy handed shippers! But, shipping is free if you are an Amazon PRIME member (available for $119 a year).
Here's the best part! There's not five pounds of seed in the bag! Care to guess why?