I have my own reasons for why I believe we went to the moon. If we were going to fake a NASA mission, why couldn't we fake going someplace a whole lot more interesting than the moon? Sure, if the Russians were going to fake something, they would think small like the moon. But we Americans would fake going someplace much nicer. I've heard Venus is great place to visit. Venusian women and all. Don't believe all that stuff about it being the hottest planet. The folks who tell you that are the same ones who think you can't go to the sun because it's so hot. Just go at night, silly!
Seriously, I agree with the earlier Cold War post that said the main motivation for going to the moon when we did was to get there before the Russians did. If you recall, they were beating us in the space race.
If we could spend 'X' amount of dollars in 1969 and walk on the moon, I might imagine that the cost, while still quite significant, would be much cheaper today. But why walk on the moon a second time? Isn't that just a needless waste of money? I don't think anyone seriously believes we can't walk on the moon with current technology and resources. So, if we haven't gone walked on the moon in the Last 10 years, this pretty much confirms in my mind that there isn't any point until you have the resources and technology to establish a semi-permanent base there. The important thing was getting there first. Once we had done it, it was pointless for the Russians to prove that they could too, IMHO.