For sure if PAO was in the state it is, they could have more leverage in negotiations, Berg is for sure the best Greek League striker, but I think his transfer price will not be anywhere near what Mitroglou's was for example. Also, PAO does not benefit much by selling Berg, apparently his previous club has 40-50% of his rights and Berg himself has 10% of any transfer fee he brings in.
I also read that Berg has a minimum fee release clause (and the offer received is lower) anyone know what the min fee is in his contract?