Adobe Photoshop Extended CS4 Upgrade is now showing up on Amazon: 

http://www.amazon.com/gp/product/B001EUDGTM The upgrade price is listed at $349.00

According to Amazon:

Photoshop CS4 Extended delivers all of the unrivaled image-editing power of Photoshop CS4 and more, including breakthrough 3D painting and editing, rich motion graphics editing, and enhanced image analysis
Paint directly on 3D models, wrap 2D images around 3D shapes, convert gradient maps to 3D objects, add depth to layers and text, and get print-quality output with the new ray-tracing rendering engine, and enjoy exporting to supported common 3D formats
Easily access every tool for nondestructive adjustment of color and tone, including Exposure and Vibrance options; quickly adjust specific areas with easier access to all the tools for creating editable pixel- and vector-based masks
Paint, add text, and clone over multiple frames of an imported video sequence with ease using single-key shortcuts
Create or modify images with a wide assortment of professional, fully customizable drawing tools, paint settings, and artistic brushes; simply drag to resize brushes and adjust for hardness as you paint and preview brush strokes