I think that this item is a luxury and would make a great baby gift for a friend or new mom.  But that is exactly it -- it's a luxury.  Do you NEED this?  Nope.  Will you be a bad mom if your baby doesn't have them?  Nope.

The leg warmers are indeed a good idea for those in between seasons when it might be a bit nippy when you're leaving the house, but warm up later in the day.  I doubt you'll be using these during the hottest of the summer months.  And during the winter, you'll probably have your baby bundled in pants or at least full tights since the "lightweight" material is not that substantial for very cold weather.

Indoors, it's a cute idea to have something to cover the baby's legs to prevent rug burn for little crawlers.  And it's one size fits all, so your 3 month old or your 12 month old can fit into it.

I got the design with the pink and red flowers all over.  It's much more brightly pictured than the photograph.  The photograph makes the red look sort of brick red or even burgundy, but in real life, it's a true fire engine red color and the pink is very pink.  I suspect that all the photos are more washed out representations of what these leg warmers actually look like.

Finally, I want to warn people that the UV thing is a gimmick.  ANY garment that covers the skin will provide some level of protection against ultraviolet rays.  The level of UV protection in garments will vary depending upon the fabric, the color, and how tightly woven the garment is.  But even then, unless you're going to subject your baby to a lot of sun exposure, the varying degree of UV protection in a garment will typically not make that big a difference.  Considering that these leg warmers are not that tightly woven (which isn't a bad thing, it actually makes them stretchier), you'll probably do even better by putting a pair of pants on your baby than using leg warmers to protect her from the sun.

All told, I still think these are a cute idea.  They're easier than removing stockings to change diapers.  But considering the price, I consider this item an unnecessary, but nice, luxury.  Again, a great gift idea.