It is between $440 and $500 some delivered to your door on
https://lebanon.jadopado.com/. Not all sellers deliver to lebanon, but it you are in a hurry, it should be here within a week. I am not sure about customs though. The cheapest one I saw is delivered from Hong Kong
https://lebanon.jadopado.com/product/JM00211076/oneplus-3-dual-sim-64gb-4g-lte. You can scroll down and it will tell you who will deliver here.