Nah, actually it isn't as much as you would think to mail internationally if you use the general post office and are only sending letters. About $1.15 US for a letter or card to send international first class - That is just 3 Forever Stamps. There is also second class and third class mail that takes longer to deliver but cheaper. 

I used to have a penapl in in Japan when I was younger. We corresponded for nearly a decade via post until we drifted apart. It was set up with the school I was attending to start. How to find one now? I am sure there are plenty of places you can look up on the net. There is also plenty of programs for people to write to Military folk stationed over seas.