How much does a police dog cost:

A dog is possibly the most important purchase for a K-9 unit.

A single-purpose dog can cost $2,500-$4,000, without training, or very little.

If you purchase a dog from a private vendor, they can be more expensive.

A dog trained for dual purpose-for both patrol and narcotics, for example-can cost $8,000-$10,000.

https://thedogvisitor.com/how-much-does-it-cost-to-train-a-police-dog

On top of that is the cost to feed and care for the dog -- quite an investment for a police force.