I'm not sure about the relation you are suggesting between block size and price determination. In the end it's the market that determines the price, so you
could easily have 10x the amount of transactions that paypal has, but if that capacity is not used - it probably won't be a variable important for price estimation.
On the other hand, if one would say that nr. of transactions matches pp, then it would make a difference, because it would suggest that user base grew, interest is growing, and ofc price goes up.