The total amount that Avion paid (including taxes) is:
[tex]250(1+0.09)=250(1.09)=272.50[/tex]dollars, and the total amount that Brandon paid (including taxes) is:
[tex]220\cdot(1+0.09)=220(1.09)=239.80[/tex]dollars.
Then, the difference in the amount Avion and Brandon paid is:
[tex]272.50-239.80=32.70[/tex]Answer: $32.70.