Use the Mana Golem bot and sell what you get. Gem of Nulgaths are 13,000g and the Member Voucher is 250,000. The quest itself gives 13,000g and the Gem of Nulgath is a very common drop so you'll get rich in no time. I always farm my gold there and I can get 2m by 8 hours or so.
Personal, I don't see a point in farming gold. Non-members can't get to Coin Collector shop and Dage doesn't have his birthday shop open. But if you insist, I'd go with what @Daezen said above. Mana Golem isn't that hard either.