$400 is really not that much for a laptop, but! for $400 you can easily find some used/refurbished laptop that can do what you’ve asked for.
Example: Acer E5 with GTX 950M and FHD display refurbished from Acer eBay (can’t post links)
There are others too. I would try and find a Dell Latitude 5550 or 5570 with a dGPU