It's true. Radio Shack continues to suck...and get worse.
I can confirm that this simple circuit can be built cheaply and quickly instead of dropping $22 on Radio Shack's gold plated equivalent. I ended up constructing the adaptor for free from parts in my junk box. Cannibalize an S-Video cable and slap on a cap and a male RCA adaptor with solder connections...and viola. The end result is completely contained, and looks like it was store bought.
Of course, when I went to Rat Shack, the helpful little bitch stayed true to form: "So, what exactly are you hooking up, anyway?". They always ask that, like somehow its their business or somehow it helps them (it doesn't!).
Most people who actually want to downgrade an S-Video signal to composite won't care about the fact that they're using gold plated connections. Sheesh. If you want a higher quality signal, don't buy the gold shit...just stick with S-video.
I first tested video out on the Apple //c display. Nothing says quality like a movie on a 6", 20 year old green monochrome monitor. I later connected it to the TV, and the picture looks fine.