Сохранение значения функции которая прибавляет значения к счетчику каждую секунду в игре кликере

//                                           ============= GLOBAL VARIABLES =============
 
var money = parseInt(localStorage.getItem('moneys')),//global player's money
    clickGain = 1,//money gain on clicker clicked =
    autoGain = 1,//parseInt(localStorage.getItem('autoGains')),//auto money gain
    interval;//auto money interval
    
if (clickGain >= 1){
        clickGain = parseInt(localStorage.getItem('clickGains'));
    }
 
 
 
 
// HTML MAIN ELEMENTS (except  shop buttons)
var element = {
    clicker   : document.getElementById("main-clicker"),//button
    money     : document.getElementById("money"),//txt
}
 
//                                          ============= GLOBAL FUNCTIONS =============
 
function addMoney() { // onClicker pressed add ClickGain
  money = money + clickGain;
  
  
  localStorage.setItem('moneys', money);
  localStorage.setItem('clickGains', clickGain);
  localStorage.setItem('autoGains', autoGain);
}
 
function updateMoney(check=true) {//update html money txt
  text = "JUMPS: " + money;
  element.money.innerHTML = text;
  if(check){checkPrices();}
  
/*if (autoGain >= 1){
        autoGain = parseInt(localStorage.getItem('autoGains'));
    }*/
 
}
function autoMoney(amount) {//auto add money every interval
  clearInterval(interval);
  interval = setInterval(function(){ money = money + autoGain; updateMoney(); }, 200 / amount);
}
 
//called when a shop Element was bought
function checkPrices() {
    //Check price for each shop element
    //unlock purchase button if enough money
    for(let i=0;i<shop.length;i++){
        if(money >= shop[i].price){
            shop[i].element.disabled = false;
        }
    }
}
//called when a shop Element was bought
function onBuy(obj) {
    //update money
    money -= obj.price;
    updateMoney(check=false);
    //localStorage.setItem('moneys', money);
    //localStorage.setItem('clickGain', clickGain);
    //localStorage.setItem('autoGain', autoGain);
    //lock every purchase buttons in shop
    for(let i=0;i<shop.length;i++){
        shop[i].element.disabled = true;
    }
}
 
//                                       ============= SHOP BUTTON CLASS =============
 
class ShopElement{
    // Object for elements in the shop.
    // New Instance Token:
    //   id -> html main element id (in Html)
    //   newprice_func -> the new price formula function
    //   onclick_func  -> the onClick function
    
    constructor (id,newprice_func,onclick_func) 
    { //constructor: called on "new ShopElement()"
        this.id = id;
        this.element = document.getElementById(id);
        this.element.onclick = this.purchase.bind(this);
        this.text_element = this.element.getElementsByTagName("b")[0];
        
        this._updatePrice = newprice_func;
        this._onClick = onclick_func;
        
        this.price = 0;
        this.purchaseLvl = 1;
        this.updatePrice();
    }
    
    //Call default functions with this as argument
    onClick(){this._onClick(this);}
    updatePrice(){this._updatePrice(this);}
    
    //Update Button's txt price
    updateText(){
        this.text_element.innerHTML = "<b>" +'$'+this.price+': ' + "</b>";}
    
    // Update Every new purchase
    update(){
        this.updatePrice(); //calculate new price
        this.updateText();  //update displayed txt
    }
    // called on Element clicked
    purchase(){
        this.purchaseLvl += 1;
        this.onClick();
        onBuy(this);
        this.update()
        checkPrices();
    }
    
}
 
//                                   =============== SHOP BUTTONS & FUNCTIONS ===============
 
//alls buttons functions ( newPriceFormula , onClick )
function newPrice1(obj){obj.price = clickGain * 25 * obj.purchaseLvl;}
function newPrice2(obj){obj.price = 250 * obj.purchaseLvl;}
function newPrice3(obj){obj.price = autoGain * 30 * obj.purchaseLvl + 900;}
function newPrice4(obj){obj.price = clickGain * 25 * obj.purchaseLvl;}
function newPrice5(obj){obj.price = clickGain * 550 * obj.purchaseLvl;}
function onClick1(obj){clickGain*=2;}
function onClick2(obj){autoMoney(this.purchaseLvl);}
function onClick3(obj){autoGain*=2;}
function onClick4(obj){clickGain*=2;}
function onClick5(obj){clickGain*=5;}
 
 
 
//all shop's buttons
shop = [
    //new ShopElement("b1",newPrice1,onClick1),
    new ShopElement("b2",newPrice2,onClick2),
    new ShopElement("b3",newPrice3,onClick3),
    new ShopElement("b4",newPrice4,onClick4),
    new ShopElement("b5",newPrice5,onClick5),
    
    //new ShopElement("b4",newPrice4,onClick3),
];
 
//                                           ================= START =================
 
// FIRST UPDATE (on page loaded)
updateMoney(); //money txt
for (let i=0;i<shop.length;i++){
    shop[i].update() //buttons txt & price
}
 
//set main clicker function onClick
element.clicker.onclick = function() { 
    element.clicker.disabled = true;
    addMoney(); updateMoney(); 
    element.clicker.disabled = false;
};