Nokia X2-01 display black spot in LCD-How much cost to repair ?

I have Nokia X2-01 and I am quite happy with phone . It is now 1 and half year old .. but there is small problem with it or I should say its a big problem because there is problem on the screen. I have a black spot on the screen on the lower left corner and it is increasing day by day. I am not sure what is the issue and how it started because I am not sure when I dropped it because I don't remember dropping it and it is also not like damage due to drop.. it is just black spot and it is increasing automatically but very slowly.

Also what would be the cost to get it fixed at nokia service center and how much it will get cost if I get it repaired at regular mobile shop ?

I think you are in trouble because the symptoms you mentioned clearly shows that your LCD screen is dying. It is actually your screen's pixels are dead it is a common problem in LCD screens , most of the time due to manufacturing defect or simply because you had a bad luck.

I think you should go and get your LCD replaced at Nokia service center and avoid any regular mobile repairing shops. Though I don't really how much they will charge but should be Around Rs. 1000 -1500 .