Rank upgrades can only be selected if the rank below them has already been acquired.
Aquaman -> Flash » Lifetime
12.49
2.50 EUR
Flash -> Iron Man » Lifetime
12.49
2.50 EUR
Iron Man -> Spiderman » Lifetime
12.49
2.50 EUR
Spiderman -> Batman » Lifetime
74.99
15.00 EUR
Batman -> Joker » Lifetime
124.99
25.00 EUR
Joker -> DEADPOOL » Lifetime
124.99
25.00 EUR