Many of the greatest yoga teachers have urged against stockpiling money. That warning seems a reasonable one for those practicing yoga to transcend their illusion of separation. After all, only a separate individual can feel a sense of ownership of anything. If we are all one, and none of us is hermetic, then what's the sense in building boundaries around assets? It's as futile as building boundaries around our egos. And feeding the boundary mentality regarding money is as diametrical to spiritual pursuit as feeding the boundary mentality regarding ego. In fact, the two are one and the same.
There are deeper-seeming drives to hording money than mere inane consumerism. For example, one might crave money for "just in case". One can imagine a thousand "What if...." scenarios which a fat bank account might be seen to assuage. But it's fantasy. We have no security in this life; no way to keep the winds of entropy at bay. We can create the illusion of baffles (very expensive to erect and utterly futile), but we can't hide behind them. All the issues of life will find you just as easily in a castle.
That said, if your basic human needs aren't being met - if you can't feed, clothe, shelter, or provide health care for your family - THAT'S a problem. But that's not about hording. As a preventative to such real problems, hording offers famously scant security. History is full of formerly hugely wealthy people (much less modestly well-heeled ones) who found themselves desperately poor. Solid social relationships and an indefatigable spirit are a far better defense against desperate poverty than hording. But few people with the disposable time and income to surf internet yoga forums face inextricable desperate poverty, anyway, so this is a moot issue.
Money can change the flavor of one's existence (silk curtains instead of cloth), but, in the end, it's all horizontal movement, not vertical. Ask any rich guy; life in a mansion, after the first couple weeks, still feels like life in a house. A Mercedes feels like a car. Any enduring elevation exists solely in the eyes of observers.
Money can make the minutae of living feel smoother, as you fling money at little problems, but so can yoga. And yoga's better. For example, a non-rich guy gets a parking ticket, writes a check for $50, sighs in exasperation, and has his day ruined. A rich guy writes a check for $50 and it doesn't ruin his day. The end result is the same; the only difference is in attitude alone. Money helps uncover a saner reaction (less buckling against the inevitable), but it's the reaction that matters, not the money (the poor guy is not helped a bit by his anguish), and yoga works better at uncovering the same exact sanity. For one thing, plenty of rich people actually do have their days ruined by things like parking tickets! For another thing, the vast majority of problems can NOT be bought off. I'm not just talking about obvious issues like love or health. Money usually fails even at the practical level. If Bill Gates finds himself in Manhattan desperately needing to quickly get from first avenue to 10th avenue during rush hour, there is no amount of money he can spend to achieve it. People striving to be Bill Gates fail to grok this. You can bet Bill Gates is extremely, accutely aware of it, though.
As for money to leave one's kids, you can't block their entropy, and smoothing out their bumps is even more futile than smoothing out your own. Those who've had their big bumps smoothed out for them grow sensitized to ever-smaller bumps! My mom, who lives an idyllic life in a condo among friends with all her needs met, frets as deeply about the weather as your typical Rwandan refugee does about food and shelter. Our lives are an endless terrified game of whack-a-mole against our perceived bumps at hand, at whatever scale they're at (all the way to princesses and peas). So the best legacy to leave kids is the example of a spiritual practice, and an ingrained awareness that it's possible to flow in harmony rather than be lost amid the perceived external turmoil.
Money does make life "easier" in some respects, but not in the sum total. Jesus was right: money usually creates less flow-in-harmony, overall. Peace is more easily found among the poor than the rich (if you are doubtful about that, you have not yet met a large and diverse enough pool of people!). Money can remove certain bumps, but our pain is never from the bumps, it's from our misperception of those bumps as external tormentors. We work tirelessly to vanquish them (using money and power as ammo), but it literally never ends...you never have enough ammo, and the bumps never disappear (and, per above, your sensitivity only increases). We need, instead, to be vanquishing our delusion of separation. The reed, unendingly assaulted by violent wind, never suffers, because it never dawned on the reed that the wind was a separate, external thing. Insofar as the reed thinks at all, it thinks it's dancing.
Finally, vast numbers of people are NOT having their basic human needs met. If we practice yoga to achieve unity, then we are them. Which means the communal screaming, visceral attempt to survive vastly transcends any puny need for a plasma tv or to horde for the misguided reasons discussed above. This is the only possible spiritual outlook, but, interestingly, it's also the only possible outlook in terms of pure ethics, as well. Have a look at this article, originally from the NY Times magazine, written by a distinguished authority on ethics:
http://www.smh.com.au/news/world/rich-can-save-the-poor/2007/01/05/1167777279120.html?page=fullpage#contentSwap1