The game is a pretty gross example of an unregulated capitalist economy. The truth is that there isn't and hasn't been for many years a way to get "rich" if you're not already rich. The real reason things are worth less now is because they became worth so much and the wealth was accumulated into the hands of a few. When some of those users quit that took a massive amount of NP out of the economy and nobody can afford to pay the insanely high prices.
The people who were rich enough to buy suap or gsword or any of those super expensive items before the dupes were the people who had an advantage from starting before everybody else and building a mall or taking advantage of things that were no longer in supply.
Even now, there's no way a legititmate player is making 100m from scratch. That would take years.
There's no longer a way for a legitimate player to build the money factories plaguing neopian society for years (malls) from scratch because the average shop size in the main marketplace is now over 800 which requires 100m+ just to get an empty shop that size.