Natty WP Premium Themes offer a mix of some very good themes with a lot of very ordinary themes that shouldn’t be considered Premium. They also have some free themes but from what I could see they were nothing to write home about.
Type: Personal, magazine-style blogs
Price: Single site: $US45.00, Developer pack license: $125, Developer Pack: $125 (12 months membership)
Studiopress make a variety of Premium Themes (12 at the time of writing). They have a pretty good deal where you can purchase all themes at one price which also comes with the accompanying support.
Their themes are centered on providing sites which are good for a small business. If you are an individual, one option is to use their blog design services after you purchase the theme to tweak it in the way you want.