CommandCondition-CustomPlayer.cs

// Also check out: https://gist.github.com/root-cause/7af0aa80b3ba67ef3de92e0d4161b575
using GTANetworkAPI;

namespace PreCommandTest
{
    // Custom player class - an alternative to using GetData/SetData (and probably more) in 1.1+
    public class CustomPlayer : Player
    {
        public int Money { get; set; }

        // Constructor
        public CustomPlayer(NetHandle handle) : base(handle) { }
    }

    // Custom command condition - useful in preventing players from using commands they shouldn't be using, as it runs before the command
    public class RequiresMoneyAttribute : CommandConditionAttribute
    {
        public int Amount { get; set; }

        public override bool Check(Player player, string cmdName, string cmdText)
        {
            // ...or you could just cast player to CustomPlayer...
            if (player is CustomPlayer customPlayer && customPlayer.Money < Amount)
            {
                customPlayer.SendChatMessage("You can't afford to use this command.");
                return false;
            }

            return true;
        }
    }

    // Main script
    public class WithCustomPlayerExample : Script
    {
        public WithCustomPlayerExample()
        {
            RAGE.Entities.Players.CreateEntity = (NetHandle handle) => new CustomPlayer(handle);
        }

        [Command("setmoney")]
        public void SetMoneyCommand(CustomPlayer player, int amount)
        {
            player.Money = amount;
            player.SendChatMessage($"Money changed to: ${player.Money}");
        }

        [RequiresMoney(Amount = 1000000)]
        [Command("wastemoney")]
        public void WasteMoneyCommand(CustomPlayer player)
        {
            player.Money -= 1000000;

            player.SendChatMessage("$1 million gone just like that...");
            player.SendChatMessage($"Money left: ${player.Money}");
        }
    }
}

Awesome 🚀