Go to Lorencia. Go to the blacksmith and buy the first
gold weapon and sell it. It will be sold for a higher price thah
it was bought.
Note: This trick is considered cheating and may result in action
by the Mu Online Admins. It requires you to be in Lorencia or
be able to /warp (must be Level 50); or know your way there. It
also requires 100,000 Zen in starting money. Once you are at
Lorencia, talk to Liaman the Barmaid (Location: 125,133). She
sells all kinds of equipment. The item that you are looking for
is the 'Jewell Of Bless". Although it says you can buy this
for 9,000,000 Zen, you can actually buy this item for 100,000z.
Once you have brought a Jewell Of Bless, sell it again. When you
sell it, you will gain 3,000,000z. Do this repeatedly to get the
desired amount of Zen. The Jewell Of Bless can also be used to
upgrade an item's level by one.