When it comes to commercial WordPress themes, you’re going to be hard-pressed to beat the value offered by ThemesKingdom.
They offer both high quality themes and plugins for a very affordable membership price of $50/year. Their designs keep pace with modern trends and they release a minimum of two new themes every month. The theme options panel is not overly-complicated and everything related to your account is easily accessible on their website. It’s all about the product.
Overall, ThemesKingdom is awesome value for a developer who needs themes for a variety of different websites.