Of course, this is all just speculation. I'd love to talk to someone who can point out all the reasons this couldn't work so I don't have to think much about it anymore, but until then I'll just assume this could work.
- No need for tons of fuels for launch. We don't need to get there in a hurry, so even a minimal launch force would suffice even if it takes weeks or months to reach the moon.
- The same method would be used for return vehicles. If we really intend to mine the moon we would want to send the materials back very easily and with low cost. This is possible with my approach
- Launching vehicles on the way to the moon from orbit reduces the complexity and energy requirements of launching from earth.
To re-cap the 4 stages:
- Earth launcher, launch payload to meet low earth orbit module
- Low earth orbit module, launch payload to meet lunar orbit module
- Lunar orbit module, land using reclaimable material from Lunar surface
- Lunar launcher, after Lunar orbit module reclaims sufficient material, launch to lunar orbit