I had precisely 1.78 million ECD as a builder, just enough to obtain ecoleader and sit contentedly upon my throne of poor ecoleader.
Put it this way joseph melon farmed all day every day for multiple hours and he still does while performing moderation duties and thats why he sits with over 3 mil i beleive.
To answer this question, as stated above I melon farmed and tried to average around 50k/day until I had enough to achieve the goal. As for this, I strip mined with an eff 5 pick and saved nether stars until I had enough to purchase a melon sword. This process took a friend and I two weeks to obtain a sword.