There's a lot of complexity here that I don't have time to explain--but here's the short form: some things rightly cost a "percentage" of your Total AP ('TAP'). Usually these are things like defenses (extra AGI, negative Damage Modifiers, etc.).
I think even more rightly the /multiply/ your points in Defense--but that's going far, even for us. Here is a table of what I estimate some of these would cost.
NOTE: FAST is -4 vs IMP, -8 vs PEN
NOTE: The Average number is the multiple of your Total AP that it costs. The numbers for -4 DM and -8 DM are wrong (cut-and-paste error). I'll see if I can get the right ones ...