"The Contingent Consideration would entitle Praemium...

"The Contingent Consideration would entitle Praemium shareholders to receive and retain ANY EXCESS BETWEEN(the net proceeds after tax and transacation costs realised from the sale of Praemium's international operations) and (A$50 million less tax and transactions costs)."

Added some formatting to make it easier to read.

I think it means Netwealth would keep up to the equivalent of a sale worth A$50M less tax and costs, and shareholders of Praemium would get any net proceeds after tax and costs beyond that amount paid out on top of the offer. Essentially, Netwealth have valued the international operations at A$50M less tax and costs as part of the offer, and are willing to give PPS shareholders the rest of any net profit from the sale.

The gist of what you are saying is right though.