Non commercial only:
case(int(({DutyValue}+99.99)/100),x>30,x*4-60,x>20,x*3-30,x>10,x*2-10,x>5,x,5)
https://www.revenuesa.sa.gov.au/stamp-duty-vehicles/rates
Restatement of formula from website
- Minimum $5
- duty value <=1000 : $1 for every $100 or part thereof
- Duty value <=2000 : $10 + $2 for every $100 or part thereof over 1000
- Duty value <=3000 : $30 + $3 for every $100 or part thereof over 2000
- Otherwise : $60 + $4 for every $100 or part thereof over 3000
Restatement / Refactor to simplify the math
- Round duty up to nearest $100
- duty value <=500 : $5
- duty value <=1000 : $1 for every $100
- Duty value <=2000 : $2 for every $100 - $10
- Duty value <=3000 : $3 for every $100 - $30
- Otherwise : $4 for every $100 - $60