How can we get to the Moon for cheaper?

1. You need ISRU production of propellant. And no, I don't mean processing regolith, I recommend processing that lunar ice once LCROSS tells us if it is actually there and hopefully tells us if it is in a usable form, or taking a look at those mysterious active volcanic vents that apparently put out H2O, CO2 and other useful gases. Do this with robots, make a fuel dump on the Moon.

2. Once you have working ISRU you don't need to send separate ascent and descent stages like Apollo, just refuel once you're down. It's only 2km/s of delta-v.

3. Stop talking about zero-g propellant transfer.. acceleration settled propellant transfer is TRL 6 and the slight propellant penalty is cheap.

4. Put a propellant depot in LLO, now you don't need to carry propellant for your descent stage up from earth either.

5. Tug propellant from LLO back to L1 and LEO.

6. Big roomy capsules are a luxury that should come later.

7. If your capsule is that small, do you need a separate lander?

To summarize, ISRU and on-orbit propellant depots make it cheap, do that.

But I don't think you are asking the right question. The right question is always:

Why?

What is the purpose of going back? If the answer is "exploration" then you've just begged the question.. What is the purpose of exploration? The purpose has always been colonization, and if you haven't got that in mind, you'll go exploring the wrong things.

For example, Zubrin will tell you Mars is a much better target for science because there could be life still on it somewhere and finding that life will be much more interesting than publishing some papers on lunar geology. I don't disagree, but what's that got to do with colonization? If anything, it adds weight to the "let's not contaminate Mars" arguments that are against colonization. For a guy who hates the "let's find a justification" mindset of the Station/Shuttle programs, he sure can play the game.

So what should we explore on the Moon to support future colonization? And no, I don't mean "explore" in the technology maturation sense of the word, although that's important too. I mean, what should humans be sent to look at? Simply:

* Resources. Where are the volatiles we need? Where's the ice, the vents of useful gases, the metal deposits? There's only so much exploration that can be done with robots, and that exploration will be all used up in step 1. The resources they find will not last forever, they might not even be sufficient for more than a dozen expeditions.

* Sites. Where do we build? The simple fact is, the Moon is a harsh mistress. Bubble domes are sexy but I don't know how they provide radiation protection. Any sensible Moon colony will be built underground, so that's where we have to go exploring. That means caves, lava tubes, and other natural formations. The goal should be to identify how much heavy equipment will be needed to build a base.

There will be plenty of opportunities to do science along the way.