Not to go too off topic here, but that's a matter of personal preference. You don't NEED a 290 to game, but when you're playing BF4 a higher end card like the 290 makes a very noticeable difference.
You have every right to your opinion though

No, it makes almost no difference. It is overkill.
You dont even know what kind of setup the OP has. Some people have dual or even quad monitor setups, you know.
You should consider quitting gaming and just focus on mining, just a suggestion.
Geez, some people have hobbies, you know. And a couple of lucky few gamers even make more a lot more money gaming than you could with mining.