Consider this.

Complete one mission on Hard / Very Hard difficulty: $1 million (roughly)

Achievement requirement: $100 Million

Amount of times a level needs to be completed: 100 times.

Sorry Suda51, I love your games, but this is kind of stupid of you.

If you don't agree, downvote this guide and enjoy playing Mission One 86 more times.

WARNING:
It does seem to mess with your world leaderboard rankings.
Since buying this game, I have never been able to access this screen due to "Failed to access leaderboard data" screen, and assumed the leaderboards were broken.
I posted this guide under the understanding the leaderboards were removed from the game.

Thanks for confuzzy for pointing this information out.

My two cents: Grinds like these in video games are stupid. If they didn't want us messing with game files, don't leave them in the open.

First, you need to purchase the Dark Booster arm in the gift shop.

Seriously. The item that drops your earnings 90% makes all this possible.

You'll see why in a second.

Next, out of game, head to the KID folder;

Steam / SteamApps / common / KillerIsDead / KIDGame / Config

and open the file KidResult.ini


The bottom line is what nerfs your earnings when using items such as the Dark Booster.

(Since I bought Dark Booster first, I went with that item. Ulti-Mondo might work, too.)

Now, change mSalesRate_Cheat=0.1 to mSalesRate_Cheat=100.1 or higher.

(What number you put in is up to you. Just remember 1 = the base amount the game awards, and putting 100 multiplies your earnings by 10.)

Now, boot up the game, equip the Dark Booster, and head to Chapter 1 which will hopefully be your last time farming it.


As you see, playing Mission 1 on Nightmare got me 100 million.


After getting your achievement, or getting the amount of money you want for costumes, you can reduce it back to 0.01

That's it. Upvote's are appreciated, fellow grind-haters, but I'll expect a lot of downvotes for putting this up.