Bank Space Scroll

__ is a Roman Numeral from II to V, and n is either 7 or 30.
Ruby Shop:
* costs 
* costs 
On the Bank UI the costs are in Diamonds.
* for 3 Days ($.0967/day)
* for 7 Days ($.0786/day)
* for 15 Days ($.0613/day)
* for 30 Days ($.0433/day)
* for 90 Days ($.0327/day)
* for 180 Days ($.0257/day) BEST VALUE
There does not seem to be any real way to compute the real-world USD value of a Ruby, but analysis of the Diamond costs for rental shows clearly that 180 day rental is the best value, as you would expect.