Camping World has them on sale occasionally in the 10-pack. Some of the on-line LED retailers have them cheaper, but you have to gamble on the quality. Make sure you're happy with the light spectrum before you buy. I prefer Daylight for the brightness, but some prefer the Warm Whites. I've changed all my interior lights with the exception of the 3 on the bathroom vanity. Expensive? Yes, but put them on the credit card and by the time the statement comes, you'll have learned to like them.
I'm at 90% in the S&B already, but have yet to see the savings on my utility bill. But it sure helps my batteries last longer when boondocking in the RV.
