Saw this on another forum but right now Adobe is giving away their CS2 packages for free with serials included.
http://www.adobe.com/downloads/cs2_downloads/index.html
By the way - what does a person use Lightroom for if you have Photoshop?
Right now if I were to upgrade beyond the free version, I think CS5 is all I would want at the moment because it's the first one to offer "Content-Aware Fill" which looks awesome in all the youtube tutorials!
(Side Note: Adobe GoLive CS2 was later replaced by Adobe Dreamweaver)