It's not the worst deal in the world, plus Benfica aren't the easiest club to deal with.
Chelsea don't worry about price tags anyway but Ramires will probably used to fill in the void left by those that have left in the hope he'll be better than them.
And where has that come from? They never even broke British transfer record and most of the players they bought were at reasonable prices, besides they've barely spent a penny in the last three years. They certainly do care about their finances.