"...but then you have to get it back into orbit. How much propellant do you then waste doing so? "

You bring up Zuppero and talk about "waste"?

"The conditions for NSR performance are 1) a limited system energy, 2) abundant propellant in space, and 3) a mission delta V less than about 6500 m/s. The steam rocket uses far more propellant mass (water) than alternatives."

Why choose the word "waste", instead of "use".

Water has a cost even on our water planet, Earth- granted you can get a lot of it for one dollar.

I've suggested that water might be priced at around $500 per lb on the lunar surface and that with enough volume in water mining production and a decade of time, the price could lower to somewhere around $10 per lb.

I don't think it can argued that water on the lunar surface is currently worth more than $10,000 per lb nor less than $10 per lb. And in terms of a broad range for electrical power on the Lunar surface, more than $10 per kwh and less than $500 per kwh. Of course if you involving a govt, one can get wide range of possible prices, for instance on ISS they charge $2000 per kwh for "extra use", but if not extra amount is used, it's otherwise doesn't have a price.

So, I assume water costing around $500 per lb and power being about $50 kwh. And part of what I base this on is if
the price/cost is more than this, then you will not be able to export lunar water. In other words, if the price of water was $2000 per lb, and power was $200 per kwh, I don't think one can export lunar water.

So, Zuppero:
Uses 92.6 tons of water
To deliver 20 ton

185200 lbs at $500 is 92.6 million dollars
for 40,000 lb of payload.
In terms of propellent cost it's $2,315 per lb
of payload.
Or 4.63 lbs water used to deliver 1 lb of water.

With chemical rockets I assume about 1 lb of water
converted into chemical fuel per lb of payload
delivered. And I assume one could buy rocket fuel on the
lunar surface for about $2000 per lb.

"Zuppero covered water from the Moon as well...

Water Trucking from the Moon

...and didn't have to muck about with electrolysis or cryogenics."

One could say Zuppero's plan is more supportive to the lunar water miners, whereas my idea would be supportive to lunar water miners, solar or nuclear power generation on the Moon. In other words, Zuppero buys more water per 1 lb of payload delivered. But if lunar miner need lots of electrical power, they are establishing a market for electrical power on the Moon, in which other users of electrical power, could offer to pay the same amount money per kwh. Or they could pay a premuim for power on demand and excess capacity could be used to make rocket fuel. In addition one can use LHLOX for things other than rocket fuel- to power fuel cells for vehicles