Here is just one paragraph from an article found here. Please click on the link and go read it.
This article will help church people and pastors understand monthly support needs of their missionaries:
“I heard that the average person in xyz country makes $300 a month so if we give you $1500 a month your family you should be able to live like kings.”
People have heard how low the salaries in xyz country are, or read articles about how it is so much cheaper to retire overseas, or know you can get an hour long massage for $5. Therefor, you must be able to live on next to nothing. There are a number of reasons why a poor country that seems cheap when you visit can be so expensive to live. Since we serve in El Salvador I am going to use examples from here, but the same principles hold true regardless of the country your missionary is serving in.
The first thing you have to wrap your mind around is that the situation in the US is an anomaly. In the US things (food, clothes, electronics, building material, ECT) are cheap and labor is expensive. In most of the world it is the exact opposite, things are expensive and labor is cheap. That means in most poor countries luxuries like a massage that you indulge in on vacation are cheap, but day to day things you need are often more expensive.
Below I have outlines what I feel is the minimum budget for a missionary family of 4 in El Salvador to operate in a healthy way. As a reference point this budget would allow them to live at the same level as a family of 4 living in San Diego making $65,000 a year.
Costs for things like cars and furnishings are taking the average over a 5 year period. It also assumes that at this income level they will not owe any state or federal income taxes, but only social security and Medicare.
The budget comparison is a family of 4 in Escondido California (low cost suburb of San Diego) with a combined gross income of $65,004. It also assumes employer provided health insurance and matching 401k. Those who live in San Diego area know that $65,004 a year is far from living a life of luxury. You will notice that besides rent, for comparable items most things are more expensive in El Salvador. I explain why these things are more expensive in more detail towards the end.