The idea of caps instead of money is completly wrong, but I think if some big organization, eq. NCR would release "controled" flow of money that could very easily work. Slavery is not that important, it means virtualy no harm to post-capitalism.
What you said about NCR is right. Maybe it's "still" too small for that though (to influence the economy of the whole wasteland). And after thinking it twice you are right: slavery is not really important... and I think it is a great mistake. There should be less capitalism and more slavery in the Fallout world.
Or at least something like a small but quite stable capitalism or pseudocapitalism in NCR towns (companies, labor market... even syndicates?), but also a strong presence of slavery in The Den, New Reno and Vault City (and maybe some others I forgot to mention)... This is, locations were most of the work is done by slaves and not by payed workers. This feature has been developed In VC but not in other places. It was reall poor in the Den for example. Towns like Broken Hills, Modoc and Redding should have a quite independent local economy (a monetary economy of course, but a "rudimentary", less controlled one). In other words: there would not be any real global economy, but just a little influence from NCR because of the caravan trade between towns. This would make money (caps) important and accepted everywhere, but towns outside NCR would keep some degree of independence.
But keeping to the topic of the suggestion. Why apply Supply and Demand to cars, mercs, FREAKING DOGS, and all that, but not to all items? And if prices increase, why can't payment for doing boxes or shovelling shit increase? Don't you think that prices for these things should at least increase at a very slow rate and not as fast as it does now? Right now (like I already said) it feels kind of pointless to pay so much for a merc when you know it can get shot anytime.
So, alright, keep your holy Supply and Demand, but mercenaries, dog-sellers, cars dealers, etc., should know that there's a point in which few people are gonna be interested in paying them. And, forgetting about economy for a while, I think it's unfair for loners. Getting enough money for a goddamn car is a lot of work for them.
