Cheapest for small quantities? If you know someone cheaper than Cold Blooded Cafe PLEASE let me know o.O.
My freezer is stuffed full of their rats. They have good customer service (my first shipment was delayed due to UPS or Fedex whoever shipped them and they were really cold but not frozen when I received them. I emailed Desiree about it and she sent me a whole new shipment no questions asked), they ship rather quickly, and their prices are crazy good. I HIGHLY recommend them.
Did you keep the first group of rats? As long as they were still at 'fridge' temperature (about 4°C) they would be ok to re-freeze once. That's going by human food safety standards.