wjake643 :
I need a used Fortnite rig for under $100
It has to have at bare minimum Core i3 2.4 Ghz, 4 GB RAM, Windows 7/8/10 64-bit
Not happening, you also need a video card not just the base specs. Minimum specs would be pretty bad to play that game. You will be lagging, freezing and dying.
https

/fortnitehelp.epicgames.com/customer/en/portal/articles/2840925-what-are-fortnite-s-minimum-and-recommended-specifications-
Maybe if you double your budget you can find a system with a 750Ti in it or something similar on craigslist.