ya your right, cause none in my area will take em back. The one that i go to is a "mom and pop" shop and part hobby store hehe. A couple times i would ahve been a lot happier if they did take them back. But after the scare i just had it makes me feel a lot safer about what i feed to my snake.
id personally rather go to the shops that don't take the mice back. Although rare that makes it a lot more likly that your snake will get sick even if you didn't do anythng wrong. After the scare i just had with that, i would rather not take my chances.