I think, to answer your question in present terms, super positive price for 1 BTC would be around 5 Million USD.
This number is only based on USA.
If the world began using BTC as its only means of currency exchange, then 15.5 Million USD per 1 BTC.
IMO
Sounds nuts but it's actually way more accurate that winkleloss bros saying it could get to $50,000. I mean Coinbase CEO is now saying it could become the reserve currency. In the eye of a currency collapse storm which we are heading toward its not that crazy to think people would reach for the one currency that actually worked.
When the Wink Bros say $50k USD, I think they are thinking just a 1 Billion Market Cap.
That is the number as a payment processor, like VISA, Mastercard, etc (combined).
If "Dollar Collapses" or the World uses BTC as its collective global currency system/supply, then I think 5 to 15 Million USD.
I could be very wrong, I'm no economist nor mathematician.
I'm just thinking dooms day scenario for world, but most positive outcome for BTC.
EDIT:
CORRECTIONS: The 1 Billion Market Cap, that I stated above, should really be around 700 Billion Market Cap.CORRECTIONS: All Credit Card Companies (USA) combined in 2012 was 7+ Trillion Market Cap.CLARIFICATION: When I calculated my "5 to 15 Million USD" above, I was using 2014 USA Wealth to 2014 World Wealth Stats.CLARIFICATION: 2014 World Wealth = 264 Trillion USD divided by 21,000,000 BTC = 12.5 Million USD