Film puzzle

[Rafael]

I'm wondering if anyone can shed a light on this puzzle for me? I am looking through the Freestyle site in preparation for a film order. 36 exposure rolls of FP4 cost $5.29. By way of contrast, 36 exposure rolls of HP5 cost $3.99. However, 100ft. rolls of FP4 cost $42.99 while rolls of HP5 cost $43.99. Is there any reason for the different price ratios?

 

[bmattock]

I would ask that of Freestyle.