My answers below.
I am living in Kigali.
How much does it cost to live in Rwanda?
> accommodation prices : It depends on the area and the size of the house. Between USD 500 to USD 3000. But be ready to pay
a lot if you want a nice house with some nice furniture.
> public transportation fares (tube, bus etc ...) Sorry there but there is no tube here. Bus is quite cheap and taxi motos are effective and cheap.
> food prices(per month, how much does it cost you? Once again, it depends. Most of the food is imported from Kenya and Uganda. Food can be very expensive here. For ex, a can of coca light costs 1 USD.
health prices (for those who need medical insurance) sorry I don't know but will keep you updated.
> eduction prices (if you need to pay) No idea
> energy prices (oil, electricity)You pay electricity in advance (credits). I have to check how much it costs
> common bills (Internet, television, telephone, mobile phone) Internet is widely spread. MTN has a good service. Have a look a their website, same for phone. You can get DSTV but for a nice bouquet be ready to pay around USD 120 per month.
> prices of a good menu in a traditional restaurant
> prices of a beer and or a coffee in a regular pub Beer is nice Mutzig is the local beer and costs approx 1,5 USD.
> price of the cinema USD 2