I traveled a good portion of Costa Rica about 3 years ago. We traveled as far North as the Volcano Arenal,and as far South as Manuel Antonio Park. Besides the resort we stayed at,the only commercial internet access I ran across was in a town called Heredia.The internet terminals were in a McDonald''s there. Yep,you read that right :^) The only Burger King we saw was close to a town called Jaco, and it was a converted bread truck with a canopy.It''s a different world down there my friend.
Talking to the locals there,the cost of using the internet is very high.Maybe things have changed by now? Costa Rica is a very beautiful country. You will enjoy it.
Oh,on a sailing note, I did sail a small day sailor out of Puntarenas 8^)