Sample script

var blocks = {};

function onGameInitializationEvent(event){
    handleStart();
}

function onStart(){
    handleStart();
}

function onGameStoppingServerEvent(event){
    handleStop();
}

function onStop(){
    handleStop();
}

function handleStart(){
    fileManager.create("blocks.json");
    var fileJSON = JSON.parse(fileManager.read("blocks.json"));

    if(fileJSON != null)
        blocks = fileJSON;

    console.log("First plugin loaded!");

    commandManager.register(createCommand());
    eventManager.register(createEventListenerBlockBreak());
}

function handleStop(){
    fileManager.write("blocks.json", JSON.stringify(blocks));
}


function createEventListenerBlockBreak(){
    var eventListener = {
            listener: function(event, player) {
                //Name of the block break
                var name = event.transactions[0].original.state.type.name+"";

                //If the player is defined and the block is defined in the list of blocks, it send a message to the player that inform him how much money he received.
                if(player && blocks[name]){
                    player.sendMessage(Text.of("You received ", TextColors.GREEN, blocks[name]+" "+economyService.currency.symbol.toPlain));
                    economyService.addMoney(player, parseFloat(blocks[name]));
                }
            },
            event: org.spongepowered.api.event.block.ChangeBlockEvent.Break.class
        };

    return eventListener;
}

function createCommand(){
    var command = {
            description: "Set the amount of money to receive when you break this block.",
            permission: "job.set.amount",
            executor: function(commandSource, commandContext) {
                //If the commandSource is a player, it set the price of the block and informs the player the price has been set.
                if(commandSource instanceof Player.class){
                    commandSource.sendMessage(Text.of("You set the amount to receive for ", TextColors.GREEN, commandContext.one("blockId").get+"", TextColors.WHITE, " to ", TextColors.GREEN, commandContext.one("amount").get+""+economyService.currency.symbol.toPlain));

                    blocks[commandContext.one("blockId").get+""] = Javascript.convertJSObjectToObject(commandContext.one("amount").get);
                }
            },
            commands: ["job", "jsJob"],
            arguments: [
                {
                    format: "onlyOne",
                    name: "blockId"
                },
                {
                    format: "onlyOne",
                    type: "doubleNum",
                    name: "amount"
                }
            ]
        };

    return command;
}