OKAGE: Shadow King

This may or may not come naturally on your way to the platinum. When defeating enemies, they will either drop a money bag or a treasure chest. Money bags mean money and treasure chests mean items. You will need to have a total of 500000 Sukel on you at once. I suggest you avoid buying unnecessary things and stick to the necessities. Enemies will start off giving very little but the amount will gradually go up as you progress with the game. You will probably obtain this on your way to level 70. I suggest farming the World Library and just encounter enemies/run away until you meet an enemy group consisting of a Bad Poetry Golem & 2 Radiant Suns. This group gives a high amount of around 6000 Sukel and tons of EXP. Make sure to save at a diary beforehand because there is a chance that the Bad Poetry Golem will steal 100000 Sukel from you which is a huge setback. If this happens, just reload and try again. You can also try your luck in the Deep Grave Pit dungeon. In there, you have a chance to find the 24K Screw enemy. This enemy will always drop 9999 Sukel when defeated. However, this may not be the best route since this enemy can be very rare to encounter.