I've got one, and wouldn't sell it, but there are two problems:
1. There is no really good magazine for it. You have to experiment with various aftermarket 20 rounders and you eventually get a couple of magazines that reliably feed 17-18 rounds.
2. Although is it more accurate than a 5.45x39 AK, it is just barely so. The problem has to be the ammunition, because the quality of Alexander Arms products are really top-notch. Just taking it out of the box, it was nicer than any AR upper I had ever purchased (except my JP CTR-02). I will admit I have not tried a wide variety of 5.45 ammo with it.
I would call Alexander Arms - it would not surprise me if they had a couple left or could do one for you - when I bought mine, I had to wait for the same thing that is holding up my 6.5 Grendel - bolts. My understanding is that they did a final large run of 5.45 bolts and if they still have some they can probably get a barrel made - but when the bolts are gone there will be no more.