Situations like this are going to on for a while. In the old economy even a 1000 unit trader could recoup 3 mil in no time so it was a reasonable sum to ask. Since I started on the server I watched the base pirate tax rise from 1 mil to 2mil and even jump as high as 5 mil on some routes. With this new economy and the value it puts back into the individual credit ,pirates are going to need to learn new piracy rates, or traders will need to be more careful.
EDIT: It might be with RP to ask more sure, but in terms of mechanics higher sums are less likely to be paid.