I requested in invite months ago and haven't heard word one, so I wouldn't get my hopes up on getting one direct from the manufacturer. But, even if you could, they appear to be having QC problems; there are numerous reports of the lower part of the screen developing a yellowish cast. And OnePlus apparently is denying RMA claims for it.

Google "oneplus yellow screen".
There are suddenly a bunch of "like new" and "NIB" units on CL. Don't know if that's because they shipped a bunch recently, or if it's because people have heard about this and don't want to keep the units long enough to find out if they're affected by the screen problem.
The Find 7 is looking like a better deal. But, you can't get 'em. I almost bought one the day they released even though I didn't need it and am quite happy with my Nexus 5. Regretting it, since they're no longer available and I could probably get a good premium on CL for it.
As somebody else pointed out, though, the LG G3 has virtually identical specs/price, and is available. That's the best phone on the market right now, IMHO. If you don't need the quad screen, the LG G2 is a bargain at $400.