Worth is something only YOU can determine.
If you can afford the $40, buy the stronger cpu, or you will forever wonder if you should have.
Nice video.
It shows a couple of interesting things.
1. How games perform will depend on the game.
2. For fast action games, the cpu speed is not all important. For sims, mmo, and strategy games, the results will likely be different.
3. X4-860K as a quad is somewhat on a par with a G3258 dual core. Demonstrates the less effective AMD architecture.
4. Some of the games can make good use of more than 2 cores, others are not much impacted.