i know one but i'm looking for some better ones.
Enchanting Exploit
Basicaly you need a lot of money first of all.
Then what you do is find a stackable item at the same trader that is the weapon or item you want to enchant is at.
Double click on the stackable item so the "How Much Do You Want To Buy" window comes up
Then click on to the NPC again and find the item you want to enchant and click on it ONCE.
The "How Much Do You Want To Buy" menu will come back up then u put in how many of the item you want at once like 10.
Then you will but 10 items that you wanted to enchant but they will be stack on to each other so if you break it the enchant will be still on it.
If you break the item more than 10 times it will disappear if bought 10.
Hope it works for you it worked for me on AEL2 which is a C4 L2J server.