need help with adding model with script

hello all i got this script i just made and there's a little bug and that bug is that all the items get added in the same place so what i need help with is to make ever added item to be added away from each other

var Exp1 : Transform;
var Exp2 : Transform;
var Item1 : Transform;
var Item2 : Transform;

function Start () 
{
     Instantiate (Exp1, transform.position, transform.rotation);
     Instantiate (Exp1, transform.position, transform.rotation);
     Instantiate (Exp2, transform.position, transform.rotation);
     Instantiate (Exp2, transform.position, transform.rotation);
     Instantiate (Item1, transform.position, transform.rotation);
     Instantiate (Item2, transform.position, transform.rotation);
}

You can adjust the position by adding a certain amount on to "transform.position" in each line. For example:

var Exp1 : Transform;
var Exp2 : Transform;
var Item1 : Transform;
var Item2 : Transform;

function Start () 
{
     var origin = transform.position;
     Instantiate (Exp1, origin + Vector3( 0.4, 0, 0) , transform.rotation);
     Instantiate (Exp1, origin + Vector3( -0.4, 0, 0) , transform.rotation);
     Instantiate (Exp2, origin + Vector3( 0, 0, 0.4) , transform.rotation);
     Instantiate (Exp2, origin + Vector3( 0, 0, -0.4) , transform.rotation);
     Instantiate (Item1, transform.position, transform.rotation);
     Instantiate (Item2, transform.position, transform.rotation);
}

(In the above example I have put the original transform.position value into a temporary variable called 'origin' to make the subsequent lines a little shorter and easier to read)