Both of mine were chipped when I picked Buddy up from his neuter.
They did Bud's while he was under for the neuter and they did Sierra's right in front of me. She almost didn't notice!
I don't know for sure, but I think I paid $12 per chip at the vet, then I mailed in money to AVID to register them.
I don't care how much it was to tell you the truth, piece of mind knowing that if someone stole my dog I'd get them back is priceless!!

They both wear collars with tags when we leave the yard.
(they've gotten their jaws stuck in one another's collars too many time Wrasslin' to leave them on all the time!)