just a thought...
if one btc can cost $3k
then there is no reason 1XRP cant cost $3

( next 3-5 hours my fresh fiat will become fresh XRP

)
I think XRP can easily reach $2 by the end of this year. But let's talk about the max Ripple can reach in the far future. If all the banks will adopt it and it will replace all the money eventually, 1 XRP might be as high as $750 one day, but hardly more than that.
Here's how I came to that number:
All the money in the world =~ $75 Trillion
Max Supply of Ripple = 100,000,000,000 XRP
$75 Trillion / 100,000,000,000 XRP = 750$/XRP
Theoretically the calculus makes sense. However, i do hope we're going to see XRP at $2 by the end of this year