I generally hold Dead Money in high regard, but its message to let go of greed both does and doesn't work due to some convoluted gameplay and writing reasons.
In the conclusion, the writers intended for you to leave behind a bunch of valuable gold bars because they're too heavy to carry while escaping a deathtrap. It's supposed to symbolize needing to give up on greed, and absolutely nobody takes the lesson seriously because the game mechanics allow for several methods of getting away with the entire treasure. I didn't need anything particularly fancy, just enough sneak skills to get through one room unnoticed. When Old World Blues introduced the bullet-time Implant GRX perk, that made it even easier.
The biggest issue is the story overestimating how much I wanted the gold and the difficulty of getting it. When starting the DLC, I didn't know what to expect, and given a major part of the backstory was the Sierra Madre's financial problems and its owner's near-bankruptcy, I was more surprised the vault had money in it. Personally, I think discovering you risked your life, after many people lost their lives, for literally nothing would convey the futility of greed a lot better.
I also figured out Elijah's true objective was the Sierra Madre's advanced technology, and he's right to see that as the more valuable target. That was what I wanted too, but I can't take it, so I did make the compromise the writers wanted, just not in the way they intended. Getting the gold isn't fueling my greed, it's a disappointing consolation prize compared to siccing an invincible holographic Vera Keyes on the Legion. The main game already did something similar with the Sunset Sarsaparilla star quest, the intended reward being useless but found alongside a decent amount of money and a powerful laser pistol.
There's also the fact that the Courier has been forced through the DLC under threat of death, rather than willingly seeking a prize. Based on what I've seen of other players' frustrations, a good chunk of them would've given up and left earlier if they could, but they get stuck in the vault then decide screw it and get the gold out any way they can. The gold stops symbolizing greed and becomes last-minute compensation for all the crap the game puts you through. Maybe even an act of spite, a way to get bragging rights showing off how you broke Dead Money, only desirable because the game tries so hard to lock it away.
A lot of stories about letting go of greed like this hinge on the treasure being unattainable, the moral becoming less about not being greedy than not being stupid enough to get killed over something you won't get to use. But if you can overcome the danger and get away with it, does the greed-as-motive still matter? There are many ways to get excessive amounts of money in FNV, none of which are commented on except for cleaning out the casinos so effectively you get banned. In that case your greed was probably a net-positive because that money is more likely to benefit people through your efforts than it would in House's pockets. Anybody who knows the game well enough to get the gold definitely doesn't need the money, and can get money more easily than waiting for vendors to restock enough to sell one bar. The gold isn't valuable. It can't be valuable with how exploitable the in-game economy is.
From a roleplaying perspective, I don't even want the gold or the technology for selfish reasons. I'm a member of the FoA, they're critically short on cash, so I sneakily slipped 1295lbs of gold into Julie Farkas' pockets. That does absolutely nothing in-game, and rather than only giving up the gold with a gun to my head, I gave it up willingly. But even then I only gave the gold away because I already farm unlimited money by spawn-camping Legion assassins. Shooting Vulpes Inculta on sight is an excellent financial decision.
I completely understand the message the story is trying to send, I ignored it anyway, I wouldn't do anything differently having thought about all this, and I have no fucking idea what lesson to take from it. Steal from the rich and give to the poor? Sure, good enough.
