You can do the terrmian beach message in a bottle quest once per character. (some say once per account, not true)
I did them on all my classes then made a new character for last empty spot saving for next class release.
1.) Make a new char if you have a free slot or buy a slot (with pearls or black pearls in cash shop)
2.) Put all your Message Bottles in your camp.
3.) Take one out with new character and use to obtain quest, sell items to obtain the money.
4.) Delete character (takes 3 days)
Go back to step 1 to do quest again for more money.
If your a new player or only want 1 character you will have 2 free slots for new characters already so you could do it twice every 3 days with this process.
Probably same process on future events or similar type items.
Showing quest can be done on different character in your account (since ppl say you can only do once per account)
I'm a liar because you can't read? Can do it once PER Character. If you have a unused character slot you can however do the quest on a character, cash in for the money after completing, delete character (takes 3 days), then make another character to replace deleted one and transfer a bottle to it & complete again.
Just like I wrote in simple steps in first post. It doesn't allow you to redo quest on a character you've completed it on already. Hence the delete & create new char to repeat. Cause there is no min lvl requirement to do it.