It will never be cost efficient to ship live rats versus driving them. This is because (as mammals) rats must be shipped the same way that a puppy would be, except in a special shipping cage so they can't chew out and with health certificates as well. So online LIVE rat sales usually just refers to ads online but you still pick up the rats in person.

If you have a local reptile club or even a semi-local facebook type group, you might be able to find a semi-local source for rats. If you start out with even the lousiest live rats from any petstore or feeder breeder, you can usually breed up a colony, then start culling for undesirable traits and get your colony shaped into a good one.

I have a great supplier of live rats semi-locally, within 45 minutes drive. I was driving each Monday when I was off work but I do have a colony and now they're breeding better so I'm only going every 2-3 weeks.