The 2019 FIDE Arbiters’Manual states the following:
a) for A‟ Category Arbiters (only IAs): 300 €
b) for B‟ Category Arbiters (only IAs): 200 €
c) for C‟ Category Arbiters: IAs 160 € FAs 120 €
d) for D‟ Category Arbiters: IAs 100 € FAs 80 €
Is the only difference between earning the FA-D category title and the FA-C category title the amount of the fee paid to FIDE or is there something else involved?
fide.com/FIDE/handbook/Regs … biters.pdf
Category A and B arbiters can be chief of any event (the very top events might opt for category A as a tie-breaker between otherwise equally desired arbiters).
Category C can be chief of a non-major continental event, deputy chief of a major continental or non-major world event, or arbiter of a major world event.
Category D can be deputy chief of a non-major continental events, arbiter of a major continental or non-major world event or assistant arbiter of a major world event.
So aside from the various fees, how does an arbiter graduate from FA-D to FA-C?
Repeating the link.
fide.com/FIDE/handbook/Regs … biters.pdf
The first two pages are how arbiters move up.
The last page has the part I copied concerning what the various levels are qualified to do.