You can create a wrapper class to generate the values. I'd imagine the class looks like this:

// controller
public class theController {
  public class wrapper {
    public wrapper(string rT, product2 p, decimal amt) {
      rowType = rT;
      rowProduct = p;
      rowAmount = amt;
    }
    public string rowType { get; set; }
    public Product2 rowProduct { get; set; }
    public decimal rowAmount { get; set; }
  }
  public list<wrapper> rows { get; set; }
  public opportunity record { get; set; }
  public theController(ApexPages.StandardController controller) {
    record = (Opportunity)controller.getRecord();
    rows = new list<wrapper>();
    decimal subTotal, grandTotal = 0;
    for(OpportunityLineItem oli:[select id,pricebookentry.product2.id,pricebookentry.product2.name,quantity,unitprice from opportunitylineitem where opportunityid = :record.id]) {
      subTotal = 0;
      for(Integer ctr = 0; ctr < oli.quantity; ctr++) {
        subTotal += oli.unitprice;
        rows.add(new wrapper('item',oli.pricebookentry.product2,oli.unitprice));
      }
      grandTotal += subTotal;
      rows.add(new wrapper('sub',null,subTotal));
    }
    rows.add(new wrapper('grand',null,grandTotal));
  }
}

<!-- thePage -->
<apex:page standardController="Opportunity" extensions="theController">
  <apex:datatable value="{!rows}" var="row">
    <apex:column headerValue="Product Name">
      <apex:outputLink value="/{!row.rowProduct.id}"  rendered="{!row.rowType='item'}">{!row.rowProduct.name}</apex:outputLink>
      <apex:outputText value="Total" rendered="{!row.rowType='sub'}"/>
      <apex:outputText value="Grand Total" rendered="{!row.rowType='grand'}"/>
    </apex:column>
    <apex:column headerValue="Total Price" value="{!row.rowAmount}"/>
  </apex:datatable>
</apex:page>

Formatting not included, I'll leave that to you.