There are all kinds of ways to compare things here.. It has been my experiance that the 4 stroke will swing the bigger end props at equal or better rpm then the 2 strokes.. When it fcomes to the smaller end of the range the 2 strokes shine... Thus torque for 4 strokes and speed for 2 strokes..
As for price I just purchased a couple Mag .91 4 stokes for 119.98 to my door.. Great running engines that will hold there own against most sport .91's... Comparing a Tower .75 to a Saito 1.00 is really going to two extemes...