Pixie Pharmaceuticals Q126-130 BPP

Pixie Pharmaceuticals is a research-based company which manufactures a variety of drugs. The purchasing manager has recently been approached by three new manufacturers to produce 3 different drugs, the following cost and price info. is provided:
Drugs:

Fairyoxide:

# of units: 20,000
Direct material cost per unit: $0.8
Direct labor cost per unit: $1.6
Direct expense cost per unit: $0.4
Fixed cost per unit: $0.8
Selling price per unit : $4.00
Imported price per unit : $2.75

Spriteolite:

# of units: 40,000
Direct material cost per unit: $1.00
Direct labor cost per unit: $1.80
Direct expense cost per unit: $0.6
Fixed cost per unit: $1.0
Selling price per unit : $5.00
Imported price per unit : $4.20

Goblinex:

# of units: 80,000
Direct material cost per unit: $0.4
Direct labor cost per unit: $0.8
Direct expense cost per unit: $0.2
Fixed cost per unit: $0.4
Selling price per unit : $2.00
Imported price per unit : $2.00

Q127 What saving/(increased cost) per unit would be made/(incurred) if Fairyoxide was purchased from the overseas producer?
A $0.85
B $0.05
C $0.45
D ($0.05)

My work/answer
(0.8+1.6+0.4+0.8) – 2.75 = $0.85
A

The right answer B
(0.8+1.6+0.4) – 2.75 = $0.05

Why weren’t the fixed costs included in the calculation (there is no mention of contribution cost)?
Also just wondering in the future if I have a question from the revision kit do you have a copy of the BPP revision kit so instead of typing the whole question I just mention the question#?

Thank you!!