There aren't many suppliers and the ones in Armenia look like the real deal to me. (I got mine from shops in Turkey). I once found a site in Georgia for the duduki but didn't feel like trying to navigate in Mkhedruli script.

You may find with instruments like this (and particularly the Turkish mey) that the bore is rough and splintery as it comes from the supplier. Since it's a tube open at both ends, it's very easy to fix. Glue some sandpaper on a dowel and once it's smooth enough use the other end of the dowel as an oiling rod. (A length of threaded steel rod is also useful as a bore polishing tool).

The reed is more critical than the instrument. Duduk reeds with the little leather binding strips up the sides are much better (mey reeds don't come that way - balabans can use duduk reeds). Get the best reeds you can afford and MAKE SURE THEY MATCH.