Assume this is NSW, I thought if the 800k land is under 2 joint names A & B, then the threshold for A & B is 412K (not A has 412k threshold and B has 412k threshold) and you can simply half the 800K, hence 800k-412k=388k x1.6%= $6160 that is payable by A & B.
In the Land Tax 2014, one note...