Let's say the point is a 9 and you want to bet:

1) $40: Place $40 and win you get $56. Put $10 on the line and $30 behind --- win and you get $55. Advantage is the place bet.

2) $50: Place $50 and win you get $70. Put $10 on the line and $40 behind --- win and you get $70. No advantage either way.

Assuming they allow greater odds ----

3) $60: Place $60 and win you get $84. Put $10 on the line and $50 behind --- win and you get $85. Advantage is on the line bet.

I think that's why most casinos allow odds at the rates of 3x,4x,& 5x