Unity3D代码重复太多

我试图让你得到足够的黄金，那么你就需要岩石，如果你得到了足够的岩石，那么你需要足够的黄金。但如果两者都有，那么你可以"升级"。但如果你两者都有，那么它就会回到你需要的黄金。

    void Update()
    {
        if(enoughgold == true & enoughrocks == true)
        {
            Upgrade.text = "Upgrade to 2014!";
        }
        if(sellrocks.gold > 9999)
        {
            enoughgold = true;
        }
        else
        {
            enoughgold = false;
        }
        if(click.rock > 2999)
        {
            enoughrocks = true;
        }
        else
        {
            enoughrocks = false;
        }
        if(enoughgold == true)
        {
            Upgrade.text = "You need 3,000 Rocks!";
        }
        else
        {
            Upgrade.text = "You need 10,000 Gold!";
        }
        if (enoughrocks == true)
        {
            Upgrade.text = "You need 10,000 Gold!";
        }
        else
        {
            Upgrade.text = "You need 3,000 Rocks!";
        }
    }

void Update()
{
    enoughgold = sellrocks.gold > 9999;
    enoughrocks = click.rock > 2999;
    if (enoughgold && enoughrocks)
        Upgrade.text = "Upgrade to 2014!";
    else if (enoughgold && !enoughrocks)
        Upgrade.text = "You need 3,000 Rocks!";
    else if (!enoughgold && enoughrocks)
        Upgrade.text = "You need 10,000 Gold!";
    else if (!enoughgold && !enoughrocks)
        Upgrade.text = "You need 10,000 Gold and 3,000 Rocks!";
}