you can get battlefield 4 for 27 dollars on amazon right now http://www.amazon.com/Battlefield-4-Xbox-One/dp/B00CXCCB64/ref=sr_1_1_title_1?s=videogames&ie=UTF8&qid=1408412415&sr=1-1&keywords=battlefield+4
I enjoyed destiny, it was fun especially with friends, but the PVP was not that good. It was a Beta after all...so it depends, what are you getting it for?
If you want to play MP,compete & shoot people, get BF4, this is where it shines. If you enjoy a deeper storyline, exploring, finding loot, I'd say Destiny. On a final note, If you plan to get BF4 for the single player campaign, you're going to have a bad time.
Going to go ahead and cast my vote for Destiny even though it's not out yet. That said, Battlefield offers large scale battles unlike anything Bungie is going to do with Destiny PVP wise. So if that's your thing, then I'd go with Battlefield.