Daililies XP quests giving good amount of gold. Do every single one.
If you reach level 46. Ask friends to help you to unlock last map of underhul. Run there, don't forget to do dailies for glinstone coins and XP dailies everyday. If you run in map open chests that are there. They are giving good amount of gold. Meanwhile you'll also get some jewels. Craft them till weak/standard/fortified and sell. When you get enough coins, go and buy sack of glinstone coins and sell in auction, extra money.