I think it's the worst example. I very much doubt we will ever see the price of, say, a car approach a billion billion dollars (or cents). It's too many zeros for people to work with on a daily basis. I think what will happen is that, at regular intervals, the old hyper-inflated currency will be replaced with a new currency that's, say, 2^32 times less than the original one.

Besides, if you think a billion billions might be reached (64 bits) then why wouldn't a billion billion billion billions also be reached (128 bits)? 128 bits seems just as arbitrary as 64 bits in this context.