In Haapsalu (the nearest town (don't know if the English call it a town, 15 000 people)) the ticket costs 60 US cents, but it did cost 40 cents a few years ago. And that's only the town bus, for that price you can go from one side of the town to another. (Not more than 5 kms).
But to get to Tallinn, it costs about 6-8 dollars I guess (100 kms).
The buses here are ok, except the size of them, there are 2 buses - a very small one and a normalsized. The normalsized one is usually almost empty (~5). But the small one is allways over capacity. When someone complained about it in the local paper, that the bus is FULL when the schoolday ends, the leader of the bus company answered that he checked and the bus was not even half-full at the beginning and end of the WORKDAY.. what an idiot.