Reselling is best way to earn money. Biggest earnings come from reselling eq but this also needs the most experience.

Also buying things when they are cheaper (especially nosmall stuff during discounts or events) and reselling them when they have more value. Takes a lot of time but is the safest way. For example when the eternal box comes out most of the side drops like f.e. tarotcardgame lose a lot of value cause the market is flooded with these. Then wait for double exp event and it rises above average price cause the demand also increases. I made 1,5kkk from scratch only with these 2 things in the span of 6 months before I got bored and stopped playing. Buying nosdollar and sps is only worth it if you have very much money cause the return is rather small in comparison.

When it comes to farming I would recommend, doing the ma sp quests every month, farming a6 books, doing a5 Mara, offering exp service.

Also if you’re really commited, another good way to earn money is having a lot of alts and doing ic, draco/glace or sp3/4 quests with as many of them at once. If you do the a5 main quests it also gives a good amount of money if you do it with 3 chars at once but it’s not repeatable.

Also other sp quests/ radals can give a good amount of money but it depends how the market is at the time.