SOURCE

var list1 = [];
var list2 = [];

 function getRandom(min, max) {
  return Math.random() * (max - min) + min;
}

for (var i=0;i<100000;i++){
  list1.push({"rid":3+i, gold:getRandom(500, 20000), diamond:getRandom(50, 200)});
  list2.push({"rid":3+i, gold:getRandom(500, 20000), diamond:getRandom(50, 200)});
}

var obj2 = _.groupBy(list2, "rid");

_.forEach(list1, function(item){
  var foundItem = obj2[item.rid];
 
  var diff = item.gold - foundItem[0]['gold'];
  item.diff = diff;
})

list1 = _(list1)
			.orderBy('diff')
			.take(100)
			.value();

  $("#output").html(JSON.stringify(list1));

<div id="output"></div>