I have a LG 42P X5D when there is a dark colour in the picture on the screen there are red dots scattered in the dark colours i would like to know how much it would cost to fix this issue the problem occurs whenever the tv is on it is worse round the left edge of the tv

This is a common fault on all LG sets with few people offering any solutions. I can offer a solution that could remove 95% if not 100% of the dots.
Remove the back of the set, there are about 40 screws. On the left hand side on a circuit board you will see 3 or 4 blue plastic boxes with yellow screw adjusters in them. The only 2 you are interested in are VR3 "setup" and VR2 "setdn". Mark the location with a marker pen so that you know where the factory settings were. Then turn VR3 fully clockwise. If this does not get rid completely do the same with VR2. This worked for me today, I was about to throw the TV away but I now have a 95% improved screen, sharper and more vibrant picture and saved hundreds. It only took about 20 minutes to do too. Hope it works.