For those taking the The Bank Heist Destiny 2 quest to try their luck in reaching the Witherhoard Catalyst for the Arrivals Season, you need a lot of Filthy Lucre. Specifically, you will need 300 of them to unlock the next stage of the quest. That doesn't even affect the other two stages, which include 200 Grenades Launcher Multikills and 100 Grenade Launcher Guardian Eliminations. While the last two quest steps are straightforward, getting Filthy Lucre is a bit obscure. Here's what you need to do and how to go about it.
The only way to get Filthy Lucre is by completing Nightfalls, Crucible, or Gambit matches. It doesn't matter if you win or lose the game. You just need to successfully complete them and you will receive a Filthy Lucre. This means that you must complete between 300 Gambit, Crucible, or Nightfalls during the arrivals season. You can start grinding at any time during the game. However, there are ways to speed it up.
During the Arrivals Season Pass, at levels 11 and 22, you will receive a catalyst upgrade for those two levels. At 11th level, the buff gives you double the objective progression of the Catalyst Quest, and the second at 22th level gives you triple. After hitting level 22, it should be a walk in the park and shouldn't contain up to 300 different matches from any of the playlists.
The catch with these two improvements is that they are part of the pay track. You can only receive them if you have paid for the Arrival Season pass. If you bought it, you are in good shape. No, you still have to wait to reach level 35 to receive the Witherhoard in the first place.