Addition Not Working??

Here is the very simple code:

function setDealerListPricing(name, type)
{
if (type == 'custitem_ecs_pricesheet')
{
  var inPriceList = nlapiGetFieldValue('custitem_ecs_pricesheet');
  var specialDealer = nlapiGetLineItemMatrixValue('price', 'price', 5, 1);
  var bidPrice = nlapiGetLineItemMatrixValue('price', 'price', 2, 1);
  var itemCost = nlapiGetFieldValue('cost'); //Cost is currently not in NetSuite
  var itemWeight = nlapiGetFieldValue('weight');
  var itemMargin = nlapiGetFieldValue('custitem_ecs_margin');
  var freightCharge = nlapiGetFieldValue('custitem_ecs_freight');
  var freightCalc = (itemWeight / 2000) * freightCharge;
  var manPrice = specialDealer + freightCalc;

  var minPrice = bidPrice + freightCalc;
  var truckPrice = itemCost + itemMargin + freightCharge;
 
  if (inPriceList == 'T')
  {
   nlapiSetFieldValue('custitem_ecs_feedmanprice', manPrice, null, null);
   nlapiSetFieldValue('custitem_ecs_minprice', minPrice, null, null);
   nlapiSetFieldValue('custitem_ecs_truckload', truckPrice, null, null);
  
  }
  else
  {
   nlapiSetFieldValue('custitem_ecs_feedmanprice', '', null, null);