Here is a great way to increase your Infinity Sword fund. You must be able to beat the God King before attempting this.

Step 1: Go to Options while in game and Restart to Bloodline 1.

Step 2: Get defeated by the God King and wait until you get to you saying the following, "Father, I will avenge you"

Step 3: Get to the God King as fast as possible, skipping chests unless you walk by them and you don't have to fight anyone.

Step 4: Eventually you come to a door where you go straight or to the right. Click on the door and go through it.

Step 5: Fight the last enemiess and you should now be at the God King.

Step 6: Kill him whatever way possible!

Step 7: You now should get between 8000-11000 gold and a item.

Step 8: Sell all the items you have more then 1 of this to increase your gold.

Step 9: Repeat until you lose -- at level 150 it becomes significantly less fruitful due to the boss's difficulty.

Note: Once you get around Bloodline 10 that's when you want to fight as many monsters as possible since you get between 2000-6000 gold.