The pictures are no longer available on the Ebay link but the name of the dealer "gstudd" matches with the antique dealer who had it Greg Studdard.
The flag looks very old to me but after reading the discussion I think that a "reunion flag" is a very high possibility except that the end of the flag is tattered and frayed as if it were flying in the wind a very great deal which leads me to think more on the fake line. I am sure no expert and could give no difinitive answer. I have seen the 6th Ark. Hardee flag which is at the Murphreesboro battlefield it seems similar age wise to me.
To pay the kind of money this guy wants I sure would have to have an expert or three check it out carefully. That's quite a markup from what he paid on Ebay.