There's a few ways to do this. However if the amounts don't increase
according to a simple equation then I think your best bet is to use VLookup
with a lookup table.

Assume the grades are in column C and you want your tuition in column D.

Find some spot to create 2 columns, say F1:G12.
In F put the grades. In G put the tuitions.

Then in D3 (for example), you'd want this formula:

=VLOOKUP(C3,$F$1:$G$12,2,FALSE)

Art