I've used www.bigcheeserodents.com and I love it. The bags are vacuum sealed and the prices per rat are pretty cheap. I payed .85 apiece for 20 weaned.
Iv checked their prices also, but when you get into the large, and xxx large, it adds up quick. the kicker of it all is, iv looked at all of the "local" shows coming up, and the price of gas about equals out to shipping cost go figure. LOL
spooky