"I disagree with your premise that a lunar mission is less expensive than a NEO mission."
Ok.

Lunar requires delta V to land and delta V to takeoff
Nearby NEO delta V is just slightly above Lunar delta V - no landing & takeoff
Net is maybe +2 Km/sec for moon missions which means much less payload needed to LEO for the NEO mission
Less payload is less launches and less money.

Mars is less delta-v than lunar surface (if you disregard energy you can shed with aerobraking) and delta-v required to get off Mars is ignored.
Delta-v isn't the only factor that determines costs.
What the major factor determining cost is total manhours required.
Any uncertainties generally cause large increases in cost- esp when dealing with large bureaucracies and esp in they are second guessed by a Congress.

*** Forget Mars. What does delta V for Mars takeoff have to do with this? (It's probably ignored because of in-situ propellant manufacture)
The Lunar delta V DOES directly add to costs. It's mass to LEO for propellant, etc. More launches.

"Lunar requires development of a lander/return vehicle"
Not a big ticket item- total development and production could cost less than 50 million per unit
"Development of a rover"
What rover? Anyways, far less than a lander.

"R&D is not cheap these days - guess what Boeing spends on a new airplane"

I don't really know off hand- depends on plane. I just read that Gulfstream sold 3 business jets for around 60 million each to Israel.
There are a lot of factors which are critical in development costs- units production per year, how complex, how much time to build each unit, etc.

*** Units production/yr have little to do with development costs. A new Boeing airliner, a simple extention of something done many times before costs several Billion $. Maybe you WISH R&D for a lunar transfer vehicle, a lunar lander and lunar launch vehicle was cheap but it is not. The fact that a corporate jet in volume production costs $60M has next to nothing to do with R&D costs. Especially for a unique item like a lunar spacecraft.

"NEO could use a modified ISS module with lots of extra consumables, no fancy recycling - KISS"
First you need to find this NEO and then decide this is the one you want to spend billions in order to go to. Next it (or they) will have a launch window, when is this? Once you have a couple of NEOs that are selected, then we can discuss a comparison cost between going to them or the Moon. My guess is the Moon will be cheaper.

*** NEOs exist in low delta V reasonable trip time orbits. I do not have access to an orbital calculator. You're dodging the issue here. It's all about delta V which equals mass to LEO wich means cost, PLUS big R&D costs to build a unique new Lunar vehicle.

"BOTH missions could add living space via inflatables"
Yes, probably.
"Lunar missions beyond 14 days require a TBD power source"
Ok, first this would be to lunar poles, so you could probably fairly easily get 20 days of sunlight. And you wouldn't really need more than say 10 days on surface. If requirement to have more than 20 days, then you could go to another location in polar region few hundred miles away which would then give you another 2 weeks or so.

*** More delta V to go out of plane to reach the poles and get back home. Bigger spacecraft. More LEO weight. Then you need fuel to fly to another polar region. Remember you eliminated the rover R&D.

Hey, I'll play your show me the NEO and launch window game...
"Show me an exact spot on the Lunar poles where 20 days of sunlight is found"

-p