I meant to say 1660 supper / ti... but based on the rez or game they are surprisingly similar https://www.anandtech.com/bench/product/2527?vs=2542 . And let me preface this by saying 60 fps is playable in my book at least on my 4k tv which can fall back to 1080p and still be enjoyable. So like Forza 4 at 1080p Max Quality w/4x MSAA it is only a 2fps delta between the 2....
There is no GTX 1660 variant that comes anywhere close to the GTX 1080.
Even the fastest 1660 Ti is 26-40% slower than a GTX 1080. Why do you insist on him replacing his video card when there's absolutely no reason for it? It's terrible advice.
Took me about 3 seconds to find 50$ CAD 8350s on eBay
That's a regional price that likely doesn't apply internationally. When you do find ebay.ca listings that ship internationally, the shipping is outrageous, plus taxes.