[+] - Added

[+] - Added price formulas - (As requested by swerck) These are arithmetic expressions for calculating a price for the GUI. For example:
500+(100*%HP%), a player with 3 hearts (6 HP), will see this price as $1100, while another user with 10 hearts (20 HP) will see the same price as $2500. To see formula examples and another explanation on how to use them, check the config.yml in this plugin's page.

NOTE: you may notice an increased file size, this is because of the math parser dependency being built into the plugin itself.