Carlos works at an art gallery and sells paintings. He earns a 15% commission when his total sales are $5,000 or less. If he makes sales that total over $5,000 in one week, he gets a 20% commission. Carlos also earns $10 per hour that he works. Last week, Carlos earned a total of $1,900 after working 40 hours. What was the total value of the paintings that Carlos sold last week?