Contemporary consumption patterns are characterised by a permanent increase in private and public commodification. These processes usually take place in spheres of exchange in which goods become commodified, decommodified, recommodified or sacralised. Some objects may be consumed and then removed from the sphere of exchange (either permanently or temporarily). In a society which is marked by high a degree of commodification, the number of separate spheres is decreasing and exchange is literally happening everywhere. In the extreme case, everything becomes exchangeable with everything else. On the other end of the commodification continuum we would find a society with a large number of separate spheres of exchange, which in the extreme case would mean that the number of spheres of exchange equals the number of objects.
The tension between commodification and decommodification processes becomes apparent in the several spheres of exchange. Such spheres determine which objects are exchangeable with each other. Not everything may be exchanged with everything else (imperfect commodification). Certain objects can only be exchanged with certain other objects — this determines the sphere of exchange. There might be a sphere of exchange for prestige items, a sphere for subsistence items, a sphere of singularised objects and numerous other spheres. With regards to these examples, it might be very unlikely that prestige objects are being exchanged for subsistence items. Though, this may be the case under some exceptional circumstances, these spheres of exchange do usually not overlap.
Certain restricted spheres of exchanges allow commodities to be transformed into singularised objects. Within these particular spheres of exchange, objects cannot be traded as just a commodity X for an equivalent number of commodity Y. Heritage items, for instance, may fall into the category of singularised objects. Usually, these items cannot simply be bought or sold. Through singularisation and sacralisation these objects attain a unique value and simply become too sacred to being sold. It is difficult to imagine monuments, national art collections or war memorials being sold to private corporations. These objects are usually removed from the market or may become commodified at a later stage (i.e. through the process of privatisation).
These restricted spheres are not necessarily bounded to the public good. Private spheres of restricted exchange entail a similar mechanism. For an object to retain its status of a singularised item, it is usually exchanged only in a particular sphere of exchange. Postcards, stamps or swatches for instance, are attached to a certain spheres of exchange in which collectors aim to maximise the singularisation of their collected goods. This leads to a paradox: By increasing the degree of singularisation of a particular item, the collector indirectly increases the (theoretical) exchange value of the object. At this point, the object is ascribed with a price and becomes a commodity again — this, of course, threatens the very singularisation of the object. The same paradox becomes apparent when sacred objects (e.g. art, paintings) are regarded priceless, but have to be insured for a certain amount of money. The singularised item becomes an (indirect) commodity, since insuring the item means putting a price tag on it.
A particular object may be a commodity at some time and a singularised, sacred item at another. Some items may be exchangeable only with certain other items. Theoretically, there could be something like the “perfect commodity”: a commodity which is exchangeable with anything else. Probably, money itself comes close to this. In a more extreme case, we could imagine a “perfectly commodified world”: a society in which everything is exchangeable with anything else. A society in which we could put a price tag on literally everything. Or more cynically, as Oscar Wilde puts it: “[Knowing] the price of everything but the value of nothing.”