Upvote:3
I recently came accross a novel webservice where you can search from country to country level. Russia - Brazil will start at 1200 EUROs, when traveling next month.
Also not using one leg of a return ticket is only a problem if you miss the initial journey. Once you miss one flight, airlines typically will not allow you to travel further or on your return trip.
Upvote:3
First of all, welcome to the Travel.SE, my russian friend.
In Saint-Petersburg we have a cheat which can help you to get cheaper tickets - fly from Finland. If you are considering flights from Moscow, you can travel from there to Helsinki with transit via Saint-Petersburg. You can do that with cheap train, if you buy tickets in right time, and after that using numerous cheap buses from Saint-Petersburg.
Example of prices from Helsinki (you can use other airports, and get more variants).
The only thing you have to do is to get Shengen visa from Finland, and this can be a problem. But if you have such opportunity, consider this option - it is much more cheaper than fly directly from Russia.
Good luck with your travels.