On NA... man over 10 years I've been beyond fortunate, could probably list 50 different deals, but one that just came to mind was @Pats1717 trading me a Contra Force box for loose copies of Mario World and Mario Kart. I still have that box.
I don't really use eBay much if ever, but probably the only time I did was when the guy was selling a pile of grey rage wars carts for $12 each. I picked one up and ended up selling it later.
In the wild, so very many. Loose Rob for $3 at a flea market, dead mint cib final fantasy for $5, loose earthbound for $5. Random thrift store had a cib Mr Nutz for $5.