Some companies do a yearly cost, but it includes other things rather than just the listing. I think microchipping is one of the safest procedures you can do for your dog. Millions of dogs have been returned to their owners because of having a chip and there is no question of ownership when you chip. I've heard it doesn't hurt to get the chip, but I still think it's safest to put in the chip when they are being neutered, that way there's no chance of them flinching.
You might be interested in these threads.
http://www.yorkietalk.com/forums/gen...ies-found.html http://www.yorkietalk.com/forums/gen...py-ending.html
Also this thread:
http://www.yorkietalk.com/forums/off...und-story.html