First what phone do you have? You've posted this in the general ask a question section where we field questions on just about every Android device, so it could be $5 to $500.
Are you planning to DIY this project? If so have you checked YouTube? There are teardown videos there for just about every popular device, along with replacement videos with links to parts vendors for those parts.
Have you tried Google Shopping? Just enter the brand, model and "replacement screen" and that should get you some ballpark pricing.
If you feel that it may not be screen burn or that there may be an alternative to screen replacement feel free to take a picture of the screen and post it using mustang7757's link after registering an account, sorry mustang but screenshots won't show screen burn, but seeing people post screenshots of their cracked screens sure is fun.