What does Spare Change do?

Question

Locke gets an ability called Spare Change:

Activated after second monster appears in BMS and deals damage equal to current points. Be prepared to pay for it, though!

What does it mean, pay for it? What's the cost?

Answer 1

From the Final Fantasy Wiki

Spare Change is an ability usable by Locke and Vaan, learned by Locke at Level 35 and Vaan at Level 10, and costs 10 CP to equip. During BMS it damages the second enemy to enter based on the player's current score, but reduces their score afterwards. The Millionaire's Tome item allows any character to learn Spare Change.

So basically, you can do more damage the higher score you have, but it also reduces your score - the greater your score when you use it, the more damage you will do, but the more score you will lose for using it.