I think that while you are "dickering" with the seller, you need to find out whether the receiver works with the current firmware in it. The 131p firmware will soon be, if not already, outdated. Meaning that it won't decode the encrypted channels, once it's out of date.
If the firmware works for FTA, then you , at least , have THAT fact to fall back upon.
I frequently switch my Merc II from the factory firmware, 1.53 to the last pirate firmware, 7.53 , just to see if in a particular instance, one is better than the other.
In general, I'd think that factory firmware would be more efficient , since it doesn't have to contain the decryption algorithms running in a pirate box, but I'd bet that THAT is not always the case. A sad fact is that most of our boxes have not had any needed improvements since they were released. Both the Merc II and IV200 are exceptions to that general rule . Both of those receivers have been improved through several releases of firmware. The pirate stuff is updated so often , that somewhere along the line, actual improvements are added that would benefit US . See if work, but check out it's functionality is my advice .