Yup its how we do it.

10% gp = cost x 1.11

15 x 1.18

20 x 1.25

25 x 1.33

30 x 1.43

35 x 1.54

40 x 1.67

45 x 1.82

50 x 2.00

55 x 2.24

60 x 2.53

65 x 2.89

70 x 3.38

To achieve a consistent desired average one needs to matrix IMO. Login to read more.