I have Photoshop Elements 3.0, but it came with my tablet. I've seen it at stores like Sam's Club, only it's a newer version...(5.0), and it was 75 bucks...-_-;;
You can buy Adobe Photoshop online via the website. You can also get it by means that I'm not sure are allowed to explain on here.... If you can't purchase it, GIMP is a sufficient alternate. EP: Yeah, Wacom? I got Elements with that too, but I already had CS2 before it, and in comparison it's not very reasonable. I don't use PS that often anyway. I mostly work in Corel Painter. For coloring I highly suggest you use Painter or OpenCanvas. OC is free, so it's all the more efficient. Contrary to popular belief, PS isn't very good for CGing. You'll notice most artists use OC or Painter.
www.adobe.com Go to Downloads then Free Trial Download. I think it's for 30 days or something. It's better than paying about $200+ for it =/ Well, I think anyway.
Well, you have to pay for Painter, but GIMP and oC are free*. *Okay, it's been a while since I've used oC. Apperantly portal graphics has started selling it, and is requiring purchase of serial keys to download the older versions that were originally free. Sorry about that ******edness. Anyway, here's the download page for GIMP [assuming you run a Windows OS]