Storage can change value at the blink of an eye, as can the junk token which purports to represent it. The things which dictate value are supply and demand. In storage, you will pay what you need based on your demands, and the price will be determined by how much is available. If there is abundance, it it cheap, if it is scarce, it will be expensive. The same is true for the token. However, as I've pointed out, the token is by-design not scarce, because anybody can print their own substitute. The token only creates additional friction between the consumer, who wants storage, and the seller, who wants
money for their service.
If the seller ends up with a bunch of "storage tokens", what good is it for them if they want to do their grocery shopping? What good is it for paying their bills? Do you think each of these services will have their own token, and each one will present an additional layer of friction for every person who just wants to get on with their lives?
Of course this isn't the case. People will sell of whatever junk tokens they have and try to accumulate and save the most saleable commodity, which will be the one which does not depreciate, or depreciates as the slowest rate compared to any other commodity, ensuring that they will get their value's worth when they eventually want to trade it for something they need.
The seller of storage is also going to want to trade their commodity, storage, for a commodity which is more saleable than storage. They would never sell it for something less saleable than storage unless they had a direct need for that commodity. The seller will therefore, also offer their services in exchange for the most saleable commodity - the one with universal applicability which the greatest number of other people will accept in exchange for goods or services.
I suggest reading Carl Menger's "On the Origins of Money"[1] for a better understanding of how certain commodities become money.
[1]:http://monadnock.net/menger/money.html