An art teacher budgets $\$1,800$ to purchase paint sets for a class. The teacher must purchase a minimum of 120 paint sets to maintain the bulk pricing. If the teacher pays $\$8.25$ per set to purchase basic paint sets and $\$25.50$ per set to purchase deluxe paint sets, what is the maximum number of deluxe paint sets the teacher can purchase to stay within the budget and maintain the bulk pricing?