Browse Ebay. It works for me. Browse for price first and when you find ones in your budget, I highly recommend doing research before buying to see if you'd actually even enjoy them (what good is a shitty game for a good price?). Rinse, repeat until you find a few you want and can afford.

If you pay for PS Plus, try Fortnite. It isn't perfect, but it kills time. Plus it's basically PUBG, but actually playable.

none?

There's often not a lot of good options I've found that cheap, even on PS3, not just PS4. If you do have PS Plus, I mean, there's free games every month, and discounts that could get you down to $5.

Jetpack Joyride

Try shadow of Mordor, and if you enjoy it maybe get shadow of war.