Problem $3$: Costly Mistakes

Breaking News: Gervon Dexter, while playing for the University of Florida, agreed to pay Big League Advance Fund $($BLA$)15\%$ of his pre$-$tax NFL earnings for the next $25$ years in exchange for a one$-$time payment of $$436,485($read the full story here$).$ Gervon recently signed a four$-$year contract with the Chicago Bears at $1\mathrm{.}68$ mil $$/$year$,$ as a second$-$round draft pick for the NFL$.$ Assume that Gervon signed the BLA agreement and the NFL contract simultaneously, ${?}^{**}$ while interest rates were at $6\%$ for every maturity $($assume annual payments from NFL with annual compounding$).$

Estimate the present value of Gervon's mistake if he does not sign any other NFL contract ever again $($i$.$e$.,$ his NFL career ends after $4$ years$).$

Estimate the present value of Gervon's mistake, if he becomes something like the Lebron James of NFL$.$ That is$,$ if he plays for $20$ seasons extending his current contract under the same terms $($at $1\mathrm{.}68$mil$\frac{\text{\$}}{?}$ year$).$