Amazon they are way overpriced, you could get an OP5 for what they are asking. Swappa, as you mentioned, are starting around the 400 mark. The only issue is I don't believe you can get a warrantied version. Oneplus' policy is that the warranty only stays with the original purchaser so it is voided when the phone is sold. At the moment, since the 5 release, they are only selling 3t's in India if I remember correctly. If you grab one though, it is an excellent phone. Faster than anything running the SD821 or lower and keeps up with most new phones running the 835. Even outpaces the S8 in the ram management category (just look up S8 vs 3T speed test on youtube). There is a substantial amount of development community behind the phone as well, especially on XDA. But for the price you are going to find a 3T for, you may just want to go for the OP5 if you are concerned about the warranty. If you happen to pick up the 3T just make sure to get a decent case. I use spigens and they are very sturdy and rather slim still. It's a strong phone, it holds up well without one but for screen protection a good case will help allot. Hope my 2 cents help lol. Good luck.