Buddy i am just suggesting Vipin to have OE armrest and i think armrest is not about cost, its about the comfort it provides. When i bought mine aftermarket armrest were there at dirt cheap prices just like now. But i just went in for the reliable product, that is what i am suggesting Vipin as simple as that. Not only i am talking about your armrest, but all of the aftermarket ones are the same.
Vipin why don't you check some other car's OE armrest and see if it is feasible to install that in your polo.