Mine are both chipped. Homeagain costs $45 dollars at my vet, plus you have to pay to register online.
There is a recent law that requires all new microchip readers to be able to read all the different chips. Otherwise, you need the manufacturers reader to be able to read your chip and most places don't bother to get all the readers. Hopefully, the multi-readers will be distributed eventually.
So, even if your dog is microchipped, doesn't guarantee that you'll get it back. I do like the fact that I can prove that it's my dog and it's a permanent identification. (Also, one of my dogs also has a tattoo.)