It's a good idea to become suspicious whenever something seems precious: elegant jewelry and fragrances, exquisite fabric and other choice materials in clothing, collector's items, rare foods, tickets for exclusive 'once in a life time' events, ... whenever something in this vein appears on the horizon and presents itself in a desirable light, better be on the lookout.
Preciousness is something we talk ourselves into: its components are typically some pleasure we enjoy and some sense of rareness about that which gives us the pleasure. Sometimes it's not rareness, but some other kind of difficulty in getting it: if it requires hard work, or patience over some extended time, or giving up something else for it, then after we've invested that we are much less likely to view the thing we got in return realistically. We measure it up against the investment we did, not against what it really is worth for us (for our success in living our life, and becoming the person we want to be).
It's not difficult to see how this can fall victim to all kinds of manipulation. 'Playing hard to get' is a notoriously successful strategy for pushing up attraction. Advertisements play up the scarcity or exclusivity of some item (which is of course plenty in supply, so much so that the profits from selling it are still considerable even after subtracting the costs for those advertisements). The preciousness we're made to feel here is always artificial. The higher a price the manipulator attaches to something (while managing to still keep us wanting it), the higher we will value it. All along, in reality there's no corresponding value to that higher price. It only exists in our imagination (and the imagination is notoriously bad with numbers and ratios, too).
It seems we habitually form desires for what we perceive as rare; sometimes it's enough that someone simply puts it to us, plausibly, that this is the case with something, and we're already yearning for it. But of course, there is nothing inevitable about this habit. It's not a necessary element of our nature (if in fact, there is such a thing); it's just a habit that can be questioned, shaped, and redirected over time to not let us fall victim to erroneously valuing the wrong things.
For you may already have guessed it: once more the trick in this pattern works only with externals. (Have you ever reflected why good qualities of character, even though they're hard to achieve, never seem precious in this way to people?) At the root of the appearance of preciousness is a double act of misguided emotions: first the desire for some external good, which is mistaken already, for externals are at best something to prefer or disprefer in a given situation, they are never valuable as such — so there is no point in getting emotional about them; and secondly a kind of fear which results from recognizing the possibility (even probability) of not getting what you want. The desire sets off the fear: the more you want it, the more relevant appears the idea that you might not acquire it. The fear intensifies the desire: the more difficult or improbable it seems to get it, the higher the desire for it. As they whip up each other, they magnify an initial nothing into a wrongheaded fixation.
And thus, whenever something seems precious, it's advisable to be suspicious. Pause and consider: what makes this so desirable? Who's interested in making it look rare and hard to get? What would you really lose if you did not pursue it? The only thing that is in fact both limited and valuable is your own life time; and if you have earlier on decided to put it to work for something else, then chances are that what seems precious here is just a distraction. Take care.