Your answer for live sand is "yes". It needs no light at all, and I've had folks tell me that a completely dark live sand bed (ie, one in an enclosed cabinet sump) is great b/c it doesn't choke up with algae, but I've never had that problem.
Live rock? Yes AND no. Without the high power light, you still get the benefits of live rock (cool little critters, sponges, beneficial bacteria, etc...) but you likely won't grow much of the pretty pink/purple corraline algae. It will live on for a month or three if your tank is less than 3w per gallon or so, but it will eventually die off and you'll be stuck with a tank with expensive, brown, ugly rock.
You can grow corraline algae with normal flourescents, but you need a lot of them for most tanks to get to 3 watts per gallon.
The cost of the lighting is NOTHING compared to the cost of ruining good live rock, especially if you're stocking something like a 40 or 50g.
You can get a cheap two-strip light at Lowes for $12, and they also sell 6500K bulbs ("daylight" types, look for the "65K" or "6500K" typed somewhere on the bulb or package, this is light in the proper spectrum). I don't waste money putting expensive aquarium bulbs (like 50/50's) in these shop light fixtures b/c they burn up the bulbs too quick, so I get the cheap ones that, well, work just as good, I promise ya!.