Have to put this in perspective.
Sell prices like that only happen to Charley.
There is almost no discernable difference, EXCEPT for the rivet count.
However there are plenty of 4 rivet fans around that have the different spacing.
They are worth the same as the 5 rivet one.
What you need is long water pump fan spacing, for a short water pump clutch,
and 5 blades with 4 rivets.
I am sure that makes it crystal clear for everyone.