This might be a tough call. I have Artisteer version 2. I love it. When I have someone that has an idea of how they want their website to look, and they don't want 200 different options, I will use Artisteer.
It makes it supereasy to create a custom WordPress theme. You can use a company like 20 Dollar Banners (get a 900X200 banner for about 50 bucks)and end up with a sweet looking site (Artisteer lets you control every aspect of your site).
So what's the issue? While they don't have some of the graphical bells and whistles, premium themes like Thesis and Builder allow you to customize and control the look and feel of your site with almost the same amount of precision. Best of all, if I want to adjust my design, I can do it from an computer (where Artisteer requires me to get back to my desktop).
They have just released 3.0
The new features in Artisteer 3.0 include:
Website creation features with support for editing pages and blog posts
Web design and website samples
Support for fluid layouts (resizable sheet width)
Interactive web design preview area
Ability to specify design styles for the “Suggest” feature, generating thematic web designs (corporate, simple, retro, etc.)
Custom CSS options in Export Options
WordPress theme code based on the default WP 3.0 TwentyTen theme
Additional header and background graphics
Additional color themes
Website hosting service at www.artisteer.net (accessible from within Artisteer)
Header and footer can now be page-wide
Added transparency areas for various graphical effects
Added masked header textures (transparency areas in the texture graphics)
Yes Artisteer can be less expensive. You can start with a the $49 version or get the more advanced version for $129 (which has more graphics and has more flexibility. There is a trial version available if you want to play.
On the other hand Thesis is $87 for a single site license ($129 for a developer license) and builder is $90.
This is where I would normally put my opinion. It's a tie. I love the flexibility of Thesis (especially with the open hook plugin), and Builder (creating styles is soooo cool), and yet I love the “Wow” factor that you can create with a Artisteer created theme (again, with the right graphics). If you are a person who never travels (and only uses one computer) I might go with Artisteer. If you are always on the go, and often post blogs and podcasts from different locations and machines, you might go with a premium theme like Thesis or Builder.