EssentialsX version (/essentials): 2.01-b488

Server software (/version): latest spigot 1.8.8

By paying money less than 1 cent you can glitch the balances out.

Example: /pay name 1.000001

You balance is now glitched and you have infinite money.

Is there a way to limit the decimals?

Sorry, I'm unable to reproduce this in build 499. Can you please elaborate on "glitch the balances out"? Decimal points are not a glitch, they're a true representation of your balance.

There's a config option minimum-pay-amount which lets you limit the minimum range required to transfer money.