Hey, there are plenty of threads saying a bunch of good ways to make money, so you could easily just look them up.

Usually, for me, it's mostly just:

1. Snarbolax on elite for about 2.2k each run.
2. Use tokens to buy Snarbostuffing.
3. Sell your stuffing at the auction house.
4. Rinse and repeat. (If you aren't inclined to quit for the day after just a few runs like me.)

But if you can easily just go rinse and repeat the first 2 floors of the Royal Jelly Palace mission mindlessly until you have what you need.
As for arcade, it's not THAT bad of a money maker and it gives you a bit more variety so you'll be inclined to stay on track more.

@soulstaker
The jelly king bossfight can be diffcult if you don't have the appropriate gear. I'm not new but I still struggle to beat it first time on my alts, simply because of the equpment that you have at that level.

@OP
I run arcade and sell recipes to get money. Recipes for boss reward items (such as sealed sword/pulsar upgrades) cannot be bought at the hall of heroes or a mission lobby and so people pay good money to get them immediately.

And since you're running arcade, each run is different and slightly interesting!

Bonus: Do the arcade gate where the royal jelly palace is in stratum 4. that way you can get a 3* recipe to sell and do the boss stratum in one go, resulting in some nice cash. I'd recommend finding a vanguard friend who is willing to help you. Don't get too needy though, they also have things that they need to do.

But really, the main thing you need to make money is time. There's no quick way of getting there without investing real money. Unless you have god-tier levels of merchanting.

The nightblade is great in JK so keep it.
Keep the blaster because it knocks back monstors if you need some distance.
Switch out skelly with wolver since wolver gives attack damage medium increase (If equipped with the whole set) and it provides piercing defense.
Don't bother with the blast bomb unless you want to be a bomber.

In order to keep a little variety you may want to get a demo suit to give that bomb some love. You may want to trade out the blast bomb for the spine cone as it is easier to use (it trades the blast bomb's knockback for flinching on beast, gremlin, and fiend not that bombing most fiends is a good idea) and keep a gun as a sidearm. (as you alchemize the bombs up they eventually can incapacitate and kill masses of monsters)

SK has an abundance of sword and gun knights and severe shortage of bombers. I'm not saying you have to choose just one, but being able to bomb in the right situations is invaluable.

As someone who owns a lot of piercing swords, guns, and bombs, I feel that Dark Briar Barrage is the easiest way to deal with many fiends --- particularly devilites and gorgos. Final Flourish/BTB is a bit easier against greavers. Just about anything can handle silkwings and trojans.

The DBB is great against fiends but it is hard not to get pummeled with office equipment while trying to get in close with any bomb. On the way up to the DBB you may want to hold off on fiends unless you are feeling brave or are dealing with the slightly less common fiends such as Trojans, greavers(if you have a high enough ctr), and gorgos.