You can earn some gold buy selling items that others use to transmute, or kill evil monsters that give better drops or just continue in Catacombs and hope to get a nice drop.
Heard that is possible to sell the guild points you make when attempt master quest at 71 and get 25-50fg per guild point.
But if you plan to play ladder slasher just to earn fg, then i suggest to pick another game.
Normally games are played to relax your mind, have a good time and make new friends.
Good luck!