You can easily make your own for SO much cheaper than that. I can make about 50-60lbs of of about 75% organic food mix for my rats for around $45-$50 depending on where I shop. I use Wellness Senior dog food in small quantities as well.
That stuff looks like lab block mixture, but it has alfalfa meal in it.. Rats can't digest alfalfa, so it'd be passing right on through.