Hello, I'd like to give you my opinion about your posting and the comments from others above.
It's understandable you might feel RugPro's estimate was on the low side. However, with all due respect, you might inquire about the carpet on
Mr. Eiland's site as noted. In my opinion, the rug is certainly a much finer quality than the rug you posted for evaluation. I would venture a guess that the quality of that Tabriz rug is close to 200 knots per square inch. The rug you posted is approximately 64 Knots per square inch. As you are aware, there could be a very wide disparity in price between rugs of the same size due to this fact alone. (Note: the Eiland rug is close to 50% larger in size.)
That the two rugs were produced by the well reputed Miri brothers, would certainly be a credit and enhancement to the value of either rug. Nevertheless, it's important to consider the differences in quality, type and area of production. Also, what is their volume of production? (A closely guarded secret!)
Regarding "Renaissance" production, it's reasonable to speculate that lower quality weaves are quite plentiful and serve to benefit from (rather than enhance) the reputation of the finer antique reproductions by the same group.
All things considered, the rug you posted appears to be a very lovely carpet. When all is said and done, you may have done well on the price. Bottom line, beauty is in the eye of the beholder --- the real value of the carpet is what the buyer is willing to pay. In your case, this piece is an authentic and attractive Heriz design rug with beautiful colors. The dyes are most likely vegetable or natural. In truth, your rug might easily be valued at a considerably higher retail price in the U.S. retail market. Had you purchased the rug in Iran, the price would have been a different story, but then again, there are other associated costs (and risks) to consider. Regardless, you bought this from a dealer who is entitled to make a fair/reasonable and, hopefully, not excessive profit.
There are other parties, like the Miri Brothers maintaining similar "Renaissance" type productions in Turkey, India and Iran. And, as a result, of their efforts, they are expecting and commanding very high returns. In some cases the prices are justified, in others, not, based on what I've seen. Remember, these are mostly commercially driven productions.
In a hundred years we'll know the answer to today's question: "Who is tomorrow's Ziegler". I hope we're around to find out!
Meanwhile, take good care of your rug!