Silver Fox, remember that each score above 10 costs the resulting score minus 10. This is tallied individually. So every next score above 10 assumes you paid for the score before it as well. And reducing from 10 only gives you 1 point per score. Here I'll list out your set up and how much each parameter costs or gives you:

VIT 15 (+1+2+3+4+5=15)
CON 16 (+1+2+3+4+5+6=21)
STR 6 (-4)
DEX 3 (-7)
AGI 3 (-7)
ATT 15 (+1+2+3+4+5=15)
INT 8 (-2)
FTH 16 (+1+2+3+4+5+6=21)
PRC 8 (-2)

If we add up the costs:

+15
+21
-04
-07
-07
+15
-02
+21
-02

= +50

You want your final cost to equal exactly zero.