Chances are that you haven't seen the LG G5 on any "Best Flagship of 2016" lists. That's understandable; the build quality's a bit iffy, and it's not the best-looking piece of tech in the world. However, at just $299.99 for a brand new, unlocked unit, it's definitely worth looking into, especially since it has features that many other flagships don't even have.
This is still a 2016 flagship, so the specs are up there with the best. The G5 sports a 5.3" 1440p IPS display, a Snapdragon 820, 4GB of RAM, 32GB of internal storage and a microSD slot, a 16MP rear camera, an 8MP rear wide-angle camera, and a 2800mAh battery. It also features an IR blaster and a removable battery, which ranges from difficult to impossible to find on any other mainstream smartphone these days.
I used an unlocked AT&T G5 on T-Mobile for a few months, and it was a decent phone. The performance was incredible, the cameras captured great shots, the fingerprint sensor was quick, and being able to swap batteries and control TVs was pretty sweet. My only real gripe with it was that the display didn't get as bright as my Galaxy S7 edge's, but the 1440p panel still looks pretty good.
At the AT&T G5's MSRP of $688.99, I would have a hard time recommending the phone; however, for less than half that at $299.99, this is a great choice. The eBay seller is extremely reputable and is also offering free shipping. Since this is a sealed AT&T phone, you will need to enter the unlock code (that the seller will provide) by yourself, but that's an easy process. The phone does have a warranty, so you should be covered should it begin to bootloop (although I haven't heard of any G5s bootlooping). eBay shows that there are a "limited quantity available," so don't snooze if you're interested in picking one up.