Alex's performance in his exams is evaluated based on his average score. If his average score is 85 or above, he gets a scholarship of $1,000. If his average score is below 85, he gets a scholarship of $500. In his last four exams, he scored 88, 82, 90, and 84. How much scholarship does he get? Let's think step by step and output the final answer within \boxed{}.
user