Generating a price per item in an html table using a javascript

I have a javascript that is generating a table for me. The elements in the table are gathered in an array of arrays called sep. Sep contains 1152 sub arrays that are of the form:

Sep[0] //["316SS", "K", "-100 to 225°C", "Brass", "1/8", "4'", "4'", "8", "Ungrounded"]

So basically there are 1152 rows, each of which defines a products with 9 parameters. I want to make a for-loop that will create a price for each of the configurations. This is what I have so far:

//PART 1-------------WORKS FINE-----------------------------------
  var eopartprice2 = []; //matrix that I want to contain my prices

  for (var i = 0; i < sep.length; i++) {
  strnum1 = sep[i][5]; //parameter 5 is a length of material
  len1 = Number(strnum1.substr(0, strnum1.length - 1));

  strnum2 = sep[i][6]; //parameter 6 is another length of material
  len2 = Number(strnum2.substr(0, strnum2.length - 1));

  strnum3 = sep[i][7]; //parameter 7 is the number of units required
  condnum = Number(strnum3.substr(0, strnum3.length));

  feetOfMat = len1*len2*condnum; //The product of these is the total feet of req material

//PART 2------------PFCost always = 0.87--------------------------  
//Next i need to identify the cost of the material (to multiply by the total feet)

  var costOfMat = [0.87, 0.87, 1.77, 0.55] //different costs of the 4 materials
  if (sep[i][0] = "304SS") {
   var PFCost = costOfMat[0]; //304SS costs 0.87/foot
  } else if (sep[i][0] = "316SS") {
   var PFCost = costOfMat[1]; //316SS costs 0.87/foot
  } else if (sep[i][0] = "Inconel") {
   var PFCost = costOfMat[2]; //Inconel costs 1.77/foot
  } else if (sep[i][0] = "High Temp. Glass") {
   var PFCost = costOfMat[3]; //High Temp. Glass costs 0.55/foot
  }

  baseMatCost[i] = PFCost*feetOfMat; //I'd like to generate a matrix that
  //contains all of the base prices (1 for each row)

//PART 3---------------fitcost always = 36------------------------
//Trying to identify the cost of brass vs. stainless fittings
  if (sep[i][3] = "Brass") {
   fitcost = 36;
  } else if (sep[i][3] = "Stainless Steel") {
   fitcost = 37;
  }
}

My Problem so far is that I want the prices to be defined based off of whether or not the if statements are satisfied but in both cases (fitcost and PFCost) the values are simply the ones defined in the first if statement.

Lastly I'd like to generate my final price in the eopartprice2 matrix based off adding up the materials generated above + some cost of labor multiplied by some margin.

Also I'm concerned with the speed of how quickly this runs as it will be a live table in my website, and every time I add more to this I feel like it's taking longer and longer to generate. Here's a link to my w3 that I'm working in. http://ift.tt/2fRNQsj

Please, any help would be greatly appreciated :)