The concept of money is one of the most important inventions in humanity. It is hard to overstate what money enables by virtue of its near-universal acceptability.
Money is a valid claim only insofar its acceptability is mandated by law. It is an institution.
Money extends a trade in time. You hand over something of real value, and in return, you are given money, a claim on humanity for the future.
To hand over money to someone and expect something of value in return is an implicit celebration of this institution.
Money is the true "sanchit karma": the accumulated value, in hard numbers, of your past deeds or pedigree.
Money enables, in future. And its enable-ability is guaranteed. And therein lies the key to its charm. It is a lasso to overwhelm time. To have a million in the bank is as good as walking with an army of bodyguards, slaves, doctors, lawyers, and so on.
To have money in one's pocket is to have a command over one's environment.
Someone who shuns money, or regards its pursuit as mistaken, usually does not produce something of value for the others. Such a person has an unjustified sense of entitlement over others. Beware of the man who seeks to pick your pocket by calling its contents worthless.
Since it is a bulwark against the vagaries of time, there is no limit to how much more money one wants. As long as immortality cannot be bought, no amount of money is ever going to be enough.
The difference between greed and ambition is simple: Greed involves seeking unjust rewards. To want to steal, rob, manipulate, hoodwink, is to be greedy. To work hard, plan carefully, to want to grow, to produce something of value to others, is ambition.
Money is a form of power over others which others cannot wriggle out of. Influence, reputation, beauty are also forms of power, in that they lead to (mostly) a willing subservience. But non-monetary forms of power are neither easy to possess, nor easy to maintain.
There is the valid criticism that the pursuit of money can become self-serving, an end in itself. I find that criticism naive. Money is obviously an end in itself till it is spent. Castigating someone for only collecting money and not spending it all within the month, is to berate him for thinking further ahead than most people. Maybe he is more afraid of mortality than others, maybe he wishes to do something great for society or enable a grand sense of security for his family.
To shun money (ref Sri Ramakrishna Paramhansa) because greed is a base instinct, is to throw out the baby with the bath water. But this is a general trait, more pronounced in the East. To forget ambition, love and belonging, to see the negatives of lust, greed, attachment, and to thereby condemn women, money, relationships, and to then exhort celibacy, poverty and detachment. Humanity continues and flourishes not because of the renunciates, but because of those who struggle with, and try to balance, the rewards and sorrows of their instincts.
Of course the institution of money is corrupt, like any other institution. Of course inflation is a bit of a fraud, of course there is manipulation in commodities and in the stock markets, but the battle between greed and law will continue as long as we are human. What is the alternative? Money is here to stay. Only a progressive evolution of our institutions is our choice.
Since it is such an important institution, there is a class of industry which deals solely with the management of money and associated paper. The Financial Services Industry. It is a complex question whether they add real value to society. Certainly there are a lot of very rich people in this sector, with nary an accomplishment against their name except having made good bets due to privileged access to information, more efficient processing of money-related information, having found arbitrage opportunities, and having found interesting loopholes in the system.
Are the money-experts the baron-robbers of modern times who go away laughing from plundered cities? There is a general agreement that many of them need to be firmly reined in. But one of the strangest conundrums is: anyone who knows or understands enough about money to rein them in, joins hands with them. To thwart this very real nexus of regulators, state, financiers, requires a person of Jesus' moral strength who has memorized and understood the scriptures of Mammon and who has the warfare skills of Clausewitz. The best and the brightest join the gang, and one can easily pacify the rest with some soap opera or sport on TV.
Money, like any dopamine trigger, has diminishing psychological returns as one grows richer and richer. But even its tangible returns diminish in comparative value. In the struggle against disease and death, to have a dollar to buy an antibiotic is a far bigger leap from a position of absolute vulnerability, than for a rich man to afford another high-priced specialist in Japan.
Who doesn't struggle with the stress introduced by the pursuit of money versus the need to convince oneself that it is worth it? That convincing can, these days, take the form of media madness, "shopping" for useless junkets or fancy clothes, and outsourced pampering. To at least numb the mind somehow.
But I guess even the most distracted of money-makers would wonder at times whether it is "worth it" to do hard time in order to gain an easier time later. There is no one, or right, answer to this question.
If you are directly going bald and heart-sick in your indirect pursuit of joy and health via money, there is perhaps something wrong. It is facile to say: "live for the moment" rather than "save for the future". Both need attention. Too much of a focus on the future, and the present becomes a punishment. Too much of a focus on the present with nary a thought for the future, and may god bless you with good fortune.
The big question that seems to fox many is: "Can money buy happiness?" One is asked to observe the unhappy rich and the occasional happy poor, cleverly glossing over the luxuriating rich and the vast numbers of the unhappy poor. There are parables galore (ref the fisherman resting on the beach). It is a question which the poor are rhetorically asked, the middle classes torture themselves with, and the rich have to disregard.
The merely conceptual/tautological analysis would yield the unsatisfactory reply: Insofar as happiness can be arranged, it can be arranged better with the help of a generic enabler that money is.
Another equally unsatisfactory answer is: Having money can prevent hardship. And it can certainly lead to pleasures. Happiness, we don't know. That's your problem. Even the gurus haven't figured it out yet.
But to answer this question in earnest, one has to investigate what happiness is. In most cases, it will be found, happiness is harmony with one's surroundings, fulfilling associations with other human beings, and good mental and physical health. It is easy to see that (the pursuit of) money can be counter-productive in all three of the above aspects. Its pursuit can lead to pollution and devastation, suspicion and lack of trust, and neuroses and illnesses. And it would be ironical to then try to solve these problems which the pursuit of money introduced, with the rewards of that pursuit.
It is perhaps healthiest to consider the journey as well as the eventual pot of gold as important. To buy happiness at the mileposts as one journeys to get richer. And to continue to enjoy what doesn't cost anything. Urination and watching the stars, for example.