The Salon as a gold sink is likely ineffective with all but the the newer users. Most people find one hairstyle they like and stick with it, using wigs to cover it up when it doesn't suit their current outfit. We want more wigs. The GS wigs more often than not are poorly done, leaving a huge forehead or other off proportions. The color options from cash wigs are severely limited. I know I have loved a style many, many times, but I know I would never make an avatar with the color.
This is a very valid point. I very rarely change my base avatars hair or eyes because I don't need to any more.
Some variation would be nice as well. There are only so many variations on long flowing hair with some kind of braid, bun, or partial updo. Perhaps some more short to medium length hair, or modern styles, for non-fantasy avatars?