It depends whether or not your planning on staying anywhere or kipping in the car? Also are you planning on eating and drinking as this will cost money? Phone calls home? Soveniers?
Travelling through summer so camping/kipping in car. Food I dare say will be 50% cafe/restaurant 50% supermarket and cook. Drinks - mmm yes both rather big drinkers. Phone calls - minimal. Shopping - I'm told has to be minimal.