According to what the Essential representative told 9to5Google in a recent interview, all units of the device have been sold out before the end of 2018; what is more is that no new units will be made. The last places where you may yet have a chance of getting one are Best Buy and Amazon. EP accessories will still be produced, but other than that, the company is supposedly hard at work on the next device.
Oh well. One and half an year in the market is not bad for such a relatively unpopular product.