Three comments
1. Look at the seller's feedback. This seller has 98.5% rating and his comments to people who leave him bad feedback are off putting.
2. He describes the rug as "classic KASHAN ancient dense pattern". Anytime a seller uses "design" in his description they are in essence telling you that this isn't the real thing, ie not an Iranian rug made in Kashan.
3. When you look at the picture with the ruler showing the close up of the knots, the knots shown are all in pairs. It is likely this is a single wefted rug with 9 knots per linear inch, not 18 knots. Therefore the knot count is about 81 kpsi, not the 200+ kpsi claimed by the seller. Finally, although it is hard to see for sure, but it looks like this wool is triple ply, meaning the knots are huge.