Since the points are awarded differently depending on the range you'll need to use a case like this.
SELECT Customer
,Amount
,CASE
WHEN Amount <= 1000 THEN Amount / 100
WHEN Amount BETWEEN 1001 AND 2000 THEN (((Amount - 1000) / 100 ) * 2) + 10
WHEN Amount BETWEEN 2001 AND 3000 THEN (((Amount - 2000) / 100 ) * 3) + 30
WHEN Amount > 3001 THEN (((Amount - 3000) / 100 ) * 4) + 60
END Points
FROM MyTable
For this to work Amount needs to be a positive integer. Adjust the code as needed