A demand loan of $4000.00 is repaid by payments of $1500.00 after two years, $1500.00 after four years, and final payment after seven years. Interest is 7% compounded semi-annually for the first two years, 8% compounded quarterly for the next two years, and 8% compounded monthly thereafter. What is the size of the final payment?

(Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)