If it is Bitcoin - a decent chance - they collectively have to worth in the 100s of billions to be useful.
Yes, but that's why BTC is highly divisible. You have small currency units, like 10^-8 of 1 BTC, so life can go on even if the exchange rates seem astronomical. We might just have to come up with a new unit (something higher than Satoshi), to keep relative values sane.
It it was called bytecoin instead, we could have called the smaller unit bitcoin. But no! Satoshi had to start with the smallest unit.