These were the total costs for both of us in British Pounds (the best sort) and our time there included nearly three weeks HelpXing where we spent virtually nothing (beer was free - thanks Linda!). Around 14GBP per person per day.
We never starved and ate out most nights (either due to lack of facilities or not trusting the facilities) and it was so cheap anyway, though I did continue to lose weight during this leg of the trip (never had a food related illness though).
We had quite a few 'one-off' expenses, such as hiring snorkelling equipment in the Galapagos Islands (main costs pre-paid), couriering things back to the UK, death road mountain biking, sandboarding, horse riding etc, etc.
The following is a breakdown of the above graph. Places are in reverse order (ie, Santiago is at the top, but it was the last place we visited).