Sure from an economic POV if the total number of Bitcoins to be ever made are limited to 21 million units, then it's easy to imagine that couple of years down the line when its enough spread over the world the market cap of Bitcoins would easily reach 10 - 11 trillion dollars, making each Bitcoin worth 500K dollars (equilibrium when demand = supply). But I don't see this happening for a couple of reasons:
1- If competition enters the market (and it surely started to), and if cryptocurrency always existed couple of years from now (big IF), then the number of total cryptocurrencies in circulation will be much more than 21 million units. So even if total value of those become a couple trillion dollars (to satisfy total market demand), it will be spread over a much wider number of units and so the value of an average unit will be much lower than 500K $.
So you think there's a good chance that a bitcoin will be worth somewhere between $1000 (current value) and $500,000 in the future (that being the best case where it's the dominant cryptocurrency), and you can't justify investing $10 because of the "risk"?
Interesting thought process. For me personally, assuming I thought bitcoin had a 99% chance of total failure (i.e. crash to 0), this would still be a worthwhile investment. $10 is not a significant sum of money for me, and if the potential upside (by my own estimation) was 50,000% gains, it seems like a no-brainer. If they sold lottery tickets with those odds, I'd quit my job.