My group runs between 4 and 8 quests a day, 5 to 7 days a week and got there in 3 or 4 weeks. And we got about 1,800 Comms running all the content on EH and taking the rewards almost every time. Skipped Slayers and hardly repeated much. Ran a few raids.
Not sure how that fits in the Casual / Hard Core / Teh_Troll scale, but there you have it.
Even 3 million would be fine. Spend half your time in the off-EDs, half your time in the ones you want.