How much would this plugin cost?

[Eccat]

How hard and how much would it cost to make a plugin that allows hoppers to have the size of a chest and can be changed from storage to act like a normal hopper. I'm thinking of being able to do the following commands. I would also like to have resell rights to the plugin.
/chesthopper help - shows commands
/chesthopper reload - reload
/chestHopper - opens UI that changes the hopper type
/chestchange - automatically change the type when left clicked

Permissions:
chesthopper.autochange
chesthopper.open
chesthopper.reload

 

[Ghast]

Wrong section.

 

[Eccat]

Where should I put it? I'm not looking to buy it right now I just need a quote.

Wrong section.

 

[Ghast]

Where should I put it? I'm not looking to buy it right now I just need a quote.

Plugins section.

 

[Eccat]

$20 + $20 for resell

How long would you think it would take to make?[DOUBLEPOST=1555449886][/DOUBLEPOST]Moved to the plugins section. Thanks, Ghast!