If you are still looking for a solution, here it is:
C2=SUM(B$2:B2)
E2=IF(D2="Y",B2,0)
F2=IF(D2="Y",SUM(E$2:E2),0)
G2=$B2*IF($D2="N",VLOOKUP($C2,$K$4:$M$6,2,1),VLOOKUP($F2,$K$10:$N$12,2,1))
H2=$B2*IF($D2="N",0,VLOOKUP($F2,$K$10:$N$12,3,1))
I2=$B2*IF($D2="N",VLOOKUP($C2,$K$4:$M$6,3,1),VLOOKUP($F2,$K$10:$N$12,4,1))
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