You have the alternative of paying for university fees today for a payment of $15,000 or, you can select a payment plan where you pay $7,000 in 8 months from today and another $9,000 in exactly 20 months from today. If the interest rate is 11.3%p.a. compounding monthly, what is the advantage that the payment plan has over the upfront payment?

(expressed in present day value rounded to the nearest cent; do not show $ sign or comma separators; if the payment plan is more costly than $15,000 today, your answer will show a negative eg. -300.35)