On the first day of school, the Student Hub had 100 earbuds for sale at $1 each. At the end of the week, there were 90 earbuds left. The second week, the price of earbuds dropped to $.75 each. At the end of the week, there were 75 earbuds left. The Student Hub continued to lower the price by $.25 each week, and at the end of the fourth week, there were no earbuds left. Which price was the market clearing price?