I'd return it. The reseller you bought it from should have already realized the stuck pixel and repaired it. As for the scratches, ehhh unless your keen on how it looks I would not be too surprised as its a used laptop. But return it anyway, you can get better.
However if you wanted to be cool, you could buy that 30$ screen and fix it up yourself. But when personally when it comes to buying used laptops, I'm pretty stingy.