There is an interesting way to speculate on the potential value of bitcoin is comparing it to other global asset classes. In terms of “store of value” purposes, global precious metals are valued at $800 billion for silver, and $7 trillion for gold.
When Bitcoin establishes itself as a “money” which is accepted by many vendors, then it is suggested to compare it to the measures of currency: USD at $13.2T, EUR at $10.1T (USD), CNY at $23T (USD).
Reasonable future value of Bitcoin: $5T-15T. This is reasonable, even if it is as high as any one major currency, because it spans globally and is open to a larger total pool of buyers.
These forecasts estimate a $315k-950k price of bitcoin.
Price on BTC halving day, Nov 2012: $12.50
Price on BTC halving day, July 2016: $645
This is 50X price increase between halvings. If we were to be pessimistic and say the next halving would result in half the increase, we’re looking at 25X.
Price prediction on next bitcoin halving day in 2020: $16,000.
It’s a scenario worth considering. However, I think you’re overlooking that bitcoin is a novel asset class; as such so long as it doesn’t fail in some horrible, fundamental way, then I don’t see it falling significantly long term.