You need ALOT of time and ALOT of repeating of grindings to become successful. I have played King Server since mid 2020's and I have not donated. I did alot of grinding where i would create mg/dl and farm chaos and sell it off. All because I wanted a fenrir lmao. I remember fenrir was like 350ish bonus for the red one. I grinded like hell saving money and then selling it for bonus, ultimately I only reached my goal of buying the red fenrir because it dropped price drastically when Empire server was opened lmaoooo.
I would say Im pretty decent tho, once you get setup, you tend to make zen easier, made Elf's and bought rudolph and zen set and afk. Roamed dungeon countless amount of hours hoping to get lucky with the ancient loots lmao, it was fun. The thing about this server is that theres always something do. I spent alot of time doing all these other things , even completing the 3rd level quest took me around 1-2months with the quest item being hoarded inside my inventory for so long... At this point im still only 62rr on my SM lol...
Thus, this being said, I only speak english and not many people speak to me so i guess Ive never felt like donating to get the better items. However, if you do want to really get the most out of this game, especially if you want to participate in the guild etc (Which seems really fun id admit, but impossible if you're on bad items)I would say, you should spend bonus on the small things like FO Staff, Wings and maybe a pet, oh and especially the third quest items. Whereas the leveling up, the zen issues, just get to 90+quest and you can vote everyday and eventually when you have enough money, its actually easy to make money selling items in the market. I was really poor, now I get by fine, just that im in this absolutely slow ass pace which is why i never bothered moving to Empire cause i worked so hard and Im just hoping for a merge soon lmao