LCD screens if you can find the correct one, cost nearly as much as a new TV.
You can try to find one by, with the power disconnected from the TV, removing the back cover of the TV and locating the LCD screen part number which usually is printed on the back of the LCD panel itself.
Once you have found the number search online using just the number to see if there are any results for suppliers. Do not be surprised if the results show the manufacturer of the screen, (who do not sell individual LCD screens) as usually LCD screens are made by specialist screen manufacturers on behalf of the TV manufacturer.
The best that you may be able to do is to try and sell your TV on places like Ebay etc as faulty, good for parts to try and recoup some of the cost towards a new TV.