Quail,
A lot depends on what you already have. Personally, I would buy the following:
* PaintShop Pro $100
* Intuos2 Tablet (comes w/ Photoshop Elements 2.0 & Paiter Classic) $200
* Upgrade to Painter 8 from Painter Classic $130
This has left you with an investment of less than $500, with a lot of functionality. You can then spend some more money on plugins or hardware or whatever.
If this does become a career, you will probably want to get Photoshop CS. (Upgrade from elements for $299. See the link here:
http://www.retouchpro.com/forums/showthread.php?t=6770)
Best of Luck!
Jeff