Agree the case is not fully clear on that,
The correct way to look at it is the following:
- Consider that exactly after 5 years you can only sell the kick-start.
- You will then sell six bottles every month for the following 12 months up to the first day of year 6.
If you look at the plot, the increase from year 5 to year 6 is almost 15 k which is consistent with:
Kick-off ($30.000) + 72 bottles (18.000) - costs (13.200) =14.800
Hope you find this helpful,
please don't hesitate to contact me in case you have any doubt,