The living expenses fee offered to support your stay in Indonesia during your traineeship is usually between 1.500.000 IDR and 3.500.000 IDR (around 150-350 USD)/month. And you must be aware that it is quite a sum here in Indonesia! According to the Indonesia Salary Handbook 2009/2010 Bank Teller with a diploma makes 200-250 USD/month, Security Officer can expect 120 USD/month, Retail Assistant 150 USD/month - just to give you an idea.
Average prices of goods in Indonesia
(1USD is around 10.000 IDR)
1 liter of petrol - 6.500 IDR
Bottle of water 1,5l - 5.000 IDR
Full meal in a restaurant - 25.000 - 45.000 IDR
Nasi goreng from a street seller - 7.000 IDR
Pack of cigarettes - 12.500 IDR
5-10 bananas on local market - 5.000 IDR
Travel Agent (AC and meal) ticket from Surabaya/East Java to Denpasar/Bali - 130.000 IDR
Motorbike rental 1day/Bali Kuta - 40.000 - 80.000 IDR
Local city bus total fare - 5.000 IDR
Pair of jeans of international brand, new collection - 150.000 - 300.000 IDR
Pair of shoes international brand - 250.000 - 500.000 IDR
IDR - Indonesian Rupiah / USD - United States Dollar
Coverage of your costs might greatly exceed your basic needs. Depending on your capabilities, there will be plenty left to cover your travelling plans.
What to include in you budget
What costs other than the matching fee you need to think of? Flight ticket is the greatest of them. Usually the best way to get to your internship is to find the best deal from your initial place of departure to any major South-East Asian airport (with Singapore, Bangkok or Kuala Lumpur being the most convenient) and search for an Air-Asia airlines connection from there to Indonesia. Another thing is insurance (you can get a quote by clicking the menu on the left), vaccinations (no mandatory ones, however please consult your physician before the departure) and whatever else you want to spend on travelling and sightseeing - depending on your lifestyle and plans.
That is about the money. What else can surprise you? Well, expect that you might be asked to make looots of pictures and even give autographs! Being a foreigner in most parts of Indonesia is almost like being someone famous. And a simple exchange of smiles with someone of the opposite sex can make him or her become red of shyness and... happiness. Indonesians will suprise you many times and surely make your stay enjoyable and interesting. Lots of questions will be asked and everyone will want to try their English with you. Be ready for an amazing and sometimes crazy experience. Welcome to Indonesia :)