It's all in the macro code. Open the document and press Alt-F11 to access the VBA Editor. There you'll see:
Code:
Case 2 'The 1st row of formfields
Select Case c 'The columns of formfields
Case 2: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 9000
Case 4: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 4500
Case 6: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 6000
Case 8: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 3000
End Select
Case 3 'The 2nd row of formfields
Select Case c 'The columns of formfields
Case 2: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 8000
Case 4: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 6000
Case 6: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 4000
Case 8: If .Range.FormFields(1).CheckBox.Value = True Then i = i + 2000
Simply edit the values to suit (no formatting).