Geant is a bottling giant in Maharashtra, that is considering investing in state$-$of$-$the$-$art upgrades of its existing manufacturing unit to increase its market share. After due consideration, it has been decided that upgrading all of the plants in the remaining states where they currently run their operations is the best solution at this point. In order to do so$,$ it is evaluating all available options to finance the complete over haul of their existing plants by acquiring new machinery for each plant and come up with the most cost$-$effective solution. Evaluate the two proposals Geant has received to calculate for yourself the best solution of the two: $-$ purchase all of its own machinery for each plant, or$,$ lease them out:

Leasing out $50$ new plants $($this includes all machinery etc.$)$ would involve a total periodic payment of Rs $10$ crores per year for $5$ years.

Conversely, erecting $50$ new plants $($again$,$ this includes all machinery etc.$)$ would cost Rs $35$ crores in total which includes the cost of equipment, the installation charges etc.

The company$$s tax rate is $30\%$ and its cost of capital is $8\%.$ The tax laws allow straight$-$line depreciation for $5$ years. Explain with workings the best option to be considered.

Considering all the same values as above, would increasing the cost of capital to $10\%$ change anything? Explain with workings.