$250 is a fair price for a used PS4. For a brand new PS4 in the box? I'd keep it. I'd keep it in a closet for another 10+ years. Then i would sell it for more money. Collectors love new items in boxes.
In ways, I like that suggestion. But computers/consoles are different. I have old PC parts new in a box, and they're worth crap. It's hard to see why people would much value a PS4 later.