I think perhaps you ate looking at a limited sample as it is drawn from just one source. If you look at established indy Dommes with professional level websites and their own studios/dungeons ( or access to a professional dungeon) you may find they are a more diverse group. Although, a certain level of conventional beauty does seem to be common. I think that's just the nature of the business.

As to erotic clothing, the quality of the fetwear is usually another sign of the Domme's status, experience and level of success.

The pricing differential has never been large enough for me to play with anyone other than Domme's who might be considered top tier. Clothing, gear, studio and website quality can all be a good indicator of that.