Answer:
the privileges and immunities clause
Explanation:
Privileges and Immunities Clause is the clause 1 in the Section 2, Article IV, of the U.S. Constitution which prevents the state from treating or acting towards the citizens of the other states on the basics of any discrimination.
Given that the extra amount of $1500 is to be paid in order to get business licence for a New York resident in Illinois. This discrimination on the basics from where the person has come from violates the privileges and immunities clause.