It shouldn't be expensive. Electrician puts a switched outlet where the crown will hide it or in the attic. Trim Carpenter installs crown a few inches from the ceiling. After you move in, you measure, buy rope light at box store, snake it around, plug it in... voila. It should only cost the extra money for a switched outlet, ours was $50. We use ours for most of our lighting because it's soft and non-directional.

This is similiar to what you are talking about. We have lamp lighting but also a light on the fan and four cans centered on each wall. We don't use the fan light much but we do use the can lighting. Hope the pic helps:

Thanks for the info and the pic. For some reason I never thought of putting the can lights in the center of each wall (I was only thinking corners).
Is the rope lighting usually in set lengths?

Rope lights comes in set lengths and some can be joined together. HomeDepot had enough options for our ceiling.

How do you keep spiders from lurking in the trim of tray ceilings and cove lighting wells? This is not a joke. I keep a clean house and still had spiders fall from the sky onto the bed. I've been bitten by hobo spiders and, long ago, a black widow. Not fun.