These are for free now.
1 – Truck and Trailers
Game ready truck and trailers with attach/detach system, with good physics. Good for truck games.
https://unrealengine.com/marketplace/en-US/product/truck-and-trailers
2 – Tropical Jungle Pack
Collection of high quality photorealistic tropical forest trees, grass clusters, bushes, ferns, rocks, and river for creating a realistic forest. Suitable for your any project to become the best in visual & performance.
https://unrealengine.com/marketplace/en-US/product/tropical-jungle-pack
3 – Root Motion Extractor
Extract root motion data and transfer it to in-place animation.
https://unrealengine.com/marketplace/en-US/product/root-motion-extractor
4 – Medieval Kingdom
Medieval Kingdom is a next-gen PBR 3D modular art package which contains hundreds of fully customizable models to create your own RPG or RTS Game with First Person or Top-Down View.
https://unrealengine.com/marketplace/en-US/product/medieval-kingdom
5 – Generic Radial Menus v2.0 – Selection Wheels and Pie Menus
Quickly and easily add radial menus to your games!
https://unrealengine.com/marketplace/en-US/product/generic-radial-menus