16. (15 points) A store is offering a new smartphone on an installment plan with two options to choose from.
Option 1: Pay 800 yuan in the first month, and 200 yuan every month thereafter.
Option 2: Pay 350 yuan per month for the first half of the payment period, and 150 yuan per month for the second half.
The total payment amount and the time period are the same for both options. Find the price of the smartphone.