XRP Price if it completely replaces SWIFT

In the midst of XRP sell-offs, I came across a very positive article that seems too good to be true…

"Taking into account the limited nature of XRP (only 100 billion), and the volume of transactions through SWIFT, we get a $153-trillion-dollar market. If all this volume is stored in XRP, not including funds used to create the wallet and which are not in circulation, the value of each of the 100 billion XRP tokens would be $1530. The average value for each day in the year would be $4.19, and if you consider that there are only about 250 business days per year, it would be $6.12. But that would only be once Ripple takes over the world. For now, all we have to do is wait for news about yet another agreement with a major financial company, each of which will increase the currency’s value."
Source: http://bitcoinist.com/ripple-xrp-the-dark-horse-favorite-for-2018/

Background
The above is an extract from an article featured on Bitcoinist.com which sparked two emotions for me; initially excitement then confusion. It predicts the value of XRP in the scenario that it completely replaces the SWIFT money transfer process. However $1530 for 1 XRP seems way too high.

As a relative beginner in cryptocurrency investing (not trading as I focus on longer term), I try to read up as much as possible on the future of cryptocurrencies and how prices increase. I find that it's very difficult to explain why the price is valued as of today and how it will increase in the future. In this spirit, I am attempting to deconstruct the above statement and create my own prediction in this idealistic scenario.

Deconstruction and Analysis
In my interpretation, the statement above is based on three key assumptions, two of which I agree with:
1) The SWIFT process is a $153 trillion dollar market every year
2) There are 100 billion XRP tokens in circulation, assuming the coins in escrow are released

What I do not agree with is the third assumption:
3) If XRP completely takes over the SWIFT process, the market value would be converted into XRP

First of all, the 153 trillion figure is the volume for SWIFT transaction. This is the volume of money that is flowing every year between banks and monetary institutions. From my understanding, the way that traditional transaction works is each branch of a bank would hold a certain amount of cash reserves in the traditional currency. This poses a liquidity problem as banks would need to hold these cash reserves for the system to work. If a complete switch to XRP were to occur, then yes these reserves would be converted into XRP and the author's assumptions would work out. The price of 1 XRP would equal over $1,530.

However that is not how XRP transfers will work. What Ripple is trying to do is to solve this liquidity issue. By using XRP or xRapid, each bank would only need a much smaller reserve amount as the process is a lot cheaper and more efficient. So in fact, while there will be a rise in XRP market capital from these institutions buying the asset, the rise may not be as large as it is pictured in the statement discussed. This is not taking into account the Jevons Paradox explained by David Schwartz (Ripple's Chief Cryptographer).

Reconstruction
Taking into account the above argument, I will now attempt to create my own price prediction in the scenario that XRP completely takes over SWIFT transactions.

If we go back into the basic relationship between market cap and price we have the following formula:
Price = Market Cap / Supply

The supply is fixed (at least semi-fixed with XRP) and the only variable is market cap. Adoption by banks and financial institutions would increase market cap through their purchase of XRP as well as an increase of public popularity and purchases. The act of using XRP for payments itself does not affect the price of XRP as Fiat is converted into XRP and back again within seconds.

Now to lay my set of assumptions on top of XRP completely taking over SWIFT. I try to keep these very simple:

1. The SWIFT process is a $153 trillion dollar market every year
2. There are 40 billion XRP tokens in circulation, rounded up
3. There are $10 trillion dollars currently in the reserves of banks and institutions
4. Banks and institutions intend to rid of 90% of their reserves. The remaining $1 trillion is converted into XRP

This means Market Cap = $1 trillion and Supply = 40 billion

Therefore in this scenario, the price would be
$1 trillion / 40 billion = $25 per XRP
(Not taking account XRP market cap from other buyers)

Do let me know what you think of this logic and very basic prediction. I am in no way a financial analyst or adviser and I just want share my thoughts on the statement in the article.

Do you agree with my thought process?
Am I misinterpreting the article?
How soon will xRapid/XRP replace the SWIFT payment process?

Sources:
http://bitcoinist.com/ripple-xrp-the-dark-horse-favorite-for-2018/
https://www.quora.com/If-a-large-amount-of-banks-were-to-adopt-xrapid-and-started-using-xrp-how-would-that-impact-the-tokens-value
https://steemit.com/cryptocurrency/@j0z0r/lessons-for-cryptocurrency-newbies-1-market-cap-vs-price-per-coin