The choice of X-axis maximum and Y-axis maximum dictates the cutoff point of the quadrant. With a maximum of $80 per task, the quadrant is $3.1 and lower. If some new model gets released and costs more than $80 per task, the "most attractive" cutoff moves up from $3.1 since they have to move the X-axis max. It's completely arbitrary.

It's not saying that being inside that quadrant is a hard cut-off it's just illustrating the direction of the pareto frontier

If you take the average point inside the 4 quadrants, the top left one is pareto optimal (of the 4)