public class StoreFront2 {    
    public String message { get; set; }
    List<DisplayMerchandise> products;
    Map<Id, DisplayMerchandise> cart;

    public Id rowz;
    public id rowDel{get;set;}
    
    public PageReference shop(){
   
        handleTheBasket();
        message = 'You bought: ';
        for (DisplayMerchandise p:products){
            if(p.tempCount > 0){
               message += p.merchandise.name + ' (' + p.tempCount + ') ' ;
               }
            }
        return null;
    }
    
    public void remove(){
     rowz = (Id) ApexPages.currentPage().getParameters().get('rowDel');
        system.debug(rowz);
        if(cart.containsKey(rowz)){
            cart.remove(rowz);
    
            
        }  
         
    }

    public void handleTheBasket(){
        for(DisplayMerchandise c : products){
            if(c.tempCount > 0){
            if(cart.containsKey(c.merchandise.Id)){
                
                cart.get(c.merchandise.Id).count += c.tempCount;
                
            }
            else{
                cart.put(c.merchandise.Id, c);
                cart.get(c.merchandise.Id).count = c.tempCount;
             
          		

            } 
        
        }
        }
        
    }
    
    public Map<Id, DisplayMerchandise> getCart() {
        if(cart == null){
            cart = new Map<Id, DisplayMerchandise>();
 
                }
       
        return cart;
    }

    public class DisplayMerchandise {
        public Merchandise__c merchandise{get; set;}
        public Decimal count{get; set;}
        public Decimal tempCount{get;set;}
        public Integer rowNumber { get; set; }
        public DisplayMerchandise(Merchandise__c item){
            this.merchandise = item;
            
        }
    }

    public List<DisplayMerchandise> getProducts() {
        if (products == null){
            products = new List<DisplayMerchandise>();
    
            for (Merchandise__c item :
            [SELECT id, name, description__c, price__c
            FROM Merchandise__c
            WHERE Total_Inventory__c > 0]) {
           
            products.add(new DisplayMerchandise(item));
            }
        }
        return products;
    }

}

<apex:page standardStylesheets="false" showHeader="false" sidebar="false" controller="StoreFront2">
  <apex:stylesheet value="{!URLFOR($Resource.styles)}"/>
  <h1>Store Front</h1>
   
  <apex:form >
      <apex:dataTable value="{!products}" var="pitem" rowClasses="odd,even">
          
          <apex:column headerValue="Product">
              <apex:outputText value="{!pitem.merchandise.name}" />
          </apex:column>
          <apex:column headervalue="Price">
              <apex:outputText value="{!pitem.merchandise.Price__c}" />
          </apex:column>
          <apex:column headerValue="#Items">
              <apex:inputText value="{!pitem.tempCount}"/>
          </apex:column>
   
      </apex:dataTable>
      
      <br/>
      <apex:commandButton action="{!shop}" value="Add to Cart" reRender="msg,cart">
      
      </apex:commandButton>
  </apex:form>
  
    <apex:outputPanel id="msg">{!message}</apex:outputPanel><br/>    
    <h1>Your Basket</h1>
    
<apex:form>    
     <apex:dataTable id="cart" value="{!cart}" var="carti" rowClasses="odd,even">
			
   <apex:column headerValue="ID" rendered="false">
       <apex:outputText value="{!cart[carti].merchandise.Id}" >
         	<apex:param name='rowDel' value="{!cart[carti].merchandise.Id}" />
       </apex:outputText>
          </apex:column>
          <apex:column headerValue="Product">
              <apex:outputText value="{!cart[carti].merchandise.name}">
          	
         </apex:outputText>
          </apex:column>
          <apex:column headervalue="Price">
              <apex:outputText value="{!cart[carti].merchandise.price__c}" />
          </apex:column>
          <apex:column headerValue="#Items">
              <apex:outputText value="{!cart[carti].count}"/>
          </apex:column>
         <apex:column headerValue="Remove?">
             <apex:commandButton action="{!Remove}" value='Remove' reRender="cart"/>
         </apex:column>
                     

      </apex:dataTable>
    </apex:form>
    
  
</apex:page>