The effort towards exploitation of a ranking heuristics is not restricted to set [the most convenient for you value that you pick when you rationalize], 0 . The effort to pay off curve is flattened out at the high effort side when the higher level of efforts don't get you any better than being in the top 5.

It is clear you are rationalizing; the 5p>1 when p>0.2 (which it can be if one is to expend sufficiently greater effort towards raising p than anyone else); and thus 5p can't possibly make sense.