Uhm... I didn't really find caps to be all that much of a problem, for the most part. I mean, sure - I was usually pretty light on caps early on, but I usually got back to town with enough trade items that I could restock pretty well on ammo and meds, and the important stuff.
If you're scrounging around and collecting cups and plates and other "junk" items - my suggestion would be to focus more on looking for items that have a higher value/weight ratio - pre-war money, cigarette packs and cartons, etc. (You can even trade in scrap metal for a good sum pretty early on if you complete a couple early quests.)
Rather than have these "junk" items (cups and such, that are really there just to provide atmosphere/ ammo for the Rock-It-Launcher) have a higher value - I just think you're going about it all wrong.
Part of the minor challenge involved in scavenging items is figuring out what's worthwhile to take with you, what you might be able to get a good price for later on, what looks like it might be useful in later building your own weapons. These miscellaneous items with no real value serve a vital purpose in sort of encouraging you to discern between what's worth something and what isn't.
I first made that mistake back when I started playing Morrowind - I wasn't used to the concept of a game where you weren't supposed to clean out every place you went. But then again most games didn't have random objects you could take with you that didn't serve any purpose. I started out in Morrowind and the first place I visited, I just took everything in sight. Didn't take me too long to realize I really didn't need to be lugging around fifty pounds of cheap silverware.