It's tough to advise, especially on these Kerman rugs because some of them aren't as good a quality as others. But yes, this Kerman has some great elements to it. I would ask the seller a couple of simple questions just to figure out that it is what he says it is, also be sure to go with some payment service that can be retracted need be, and the rug is insured and wrapped to your specifications.
Ask if the rug has any stains, dry rot, repairs, color run, refringing, moth damage on front or back, odor, repair, worn areas, etc. To my eye, it looks like the rug could use a little cleaning. If the rug passess all these tests though, I would say most certainly $350 would be a very good deal.