You have the alternative of paying for gym fees today for a payment of $16,000 or, you can choose a plan where you pay $7,000 in 9 months from today and another $11,000 in 23 months from today. If interest rate is 11.6%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 $16,000 today, your answer will show a negative eg. -300.35)