Hi Bradley
Peru is a very inexpensive country for visitors so you won't need a lot of money. Your breakfasts and some meals are included so you will need money for around six lunches and six dinners, plus drinks, although this won't cost much. You could probably do it for £100-£150 but personally I would take £250 to cover food, drinks and other costs, such as souvenirs. The exchange rate is currently £1 = 4.50 Peruvian Sol, so around 1125 Sol should be plenty.
Kind regards,
Olly, your editor