In the example on page 48, Jacqueline wants to increase her Presence from 1 to 4 and needs to spend 60 points to do so. This checks out with the formula of (Current x 10), because you have to pay for each rank:
Presence 1--> Presence 2 = 10 pts
Presence 2 --> Presence 3 = 20 pts
Presence 3 --> Presence 4 = 30 pts
Hence, Presence 1 --> Presence 4 = 10+20+30 = 60 pts