termite treatment cost in arizona?

We are in the process of buying a home which is 3 years old and we noted there is a 3 foot long termite tunnel on an outside wall about 2 feet from the ground. The house is on a slab. Incidentally we had the house inspected and there are no other major problems.

Since the seller wont pay for it, and we want the house, can someone tell us an approximate cost to apply a treatment for the termites. Thanks.

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