[Q] Need help should i buy this. topic

So i found lg g2 32gb used for 5-6 months(nice saved),i bought it for 200e,but when its white screen it shows me yellow stain(haze),something like this (but just on left side and little longer ) http://forums.androidcentral.com/att...4.06.45-1-.jpg .
I had 1 month warranty and i immidentialy gave it back.The price get lowered for me to 160 e,now tell me your suggestion should i buy it,will it spread and other? And maybe can this app : https://play.google.com/store/apps/d...screen_burn_in fix the problem ?Is this a screen burn,i asked around and everyone told it was screen burn.Thanks.