Yuor budget determines a lot of this. Like what GPU to get? How much money do you have?
70 for a 3950x is excellent. Why do you have a friend if you think he might be scamming you? use a different word, like some asshole I know, or something.
Tho you need to ask yourself if you truly need a 3950x for gaming 1080p, even for a good price. It's not a gaming CPU, but for the price it'll do.