To get you totally confused ;-) I think it is for sure not made in Nain (central Iran)or even around it. Wool, Color and design are for sure east persian production. Tabbas is the lowest grade of these rugs. This one (if it really is 200 kpsi - please check your self and count if it is 14 knots in a row of 1 Inch) would then not be made in Tabbas but in Neishapoor. This production is finer than Tabbas but has the same straw like wool from east persia. Also the "silk" highlights are not natural silk. Have the dealer take one of the very white fibers around the designs out of the pile and do a burn test. Usually it is Viscose. Naishapour are the most common "Nain" rugs in finer qualtiy on the market.
On the picture from the left:
1. "Nain" Tabbas standart / Commercial, wool / viscose highlights
2. "Nain" Neishapoor / fine about 200 kpsi / wool and viscose highlights
3. Nain Original fine 9 la, kurkwool and natural silk highlights
4. Nain original very fine 6 la kurkwool annd natural silk highlights
It must be clear to you that the first two rugs are the most common on todays market and prices are what most poeple are willing to spend. The other two (real Nain) are defenently higher priced and better quality, but not available in same numbers as the cheaper ones.