Another suggestion that doesn't really work for the live at home alone pet owner.

But it does work for the pet owner that travels some.

Look into house sitters. If you have 3 pets or more that would need boarding, chances are that house sitters will be cheaper. And even if they're not cheaper or you have less pets, letting your pets stay at home with someone taking care of them is way less stressful on them that putting them in a kennel.

My wife has a couple young people she keeps ready to take care of the house when we travel. They watch the house and take care of our animals. We pay them less than what boarding would cost and they get to hang out by the pool in a quiet yard away from town.