Being able to go to the moon also provides the ability to go to deep space (just point the rocket away from the moon). Escape velocity is 11,186 m/s, so (assuming a rocket with specific impulse similar to the one in the post):

11,186 m/s = 263.1 s * 9.81 m/s^2 * ln( x kg / 20,800 kg )

That's roughly 1.58591*10^6 kg of propellant, which is actually less that what's in the first stage of a Saturn V. Of course, this doesn't include air resistance or anything beyond just hitting escape velocity and leaving Earth's orbit.