Paint Shop Pro has been on the downhill slope since version 8, which was very buggy, crashy and soured me on the line. They also ask about $20-$30
more for version 9 than any previous ones, so it's no longer the value it used to be.
Now, granted, I don't understand Photoshop. It's the standard at work and I have a licensed copy of Photoshop 7, but I have no idea how to really use it without creating dozens of layers.
For that reason, I've basically stood by Paint Shop Pro 7 until something better comes along. It does all I want it to do, I'm very used to it, and I don't care for how Gimp/Photoshop/PSP9 handle the Pen Tool that I use so frequently.
The Gimp is a program I really want to like, since it's free and all, but it has many shortcomings (mostly from a very basic UI standpoint that sparks religious war by zealots whenever it's criticized).
I would say that if you can get an educational discount, absolutely buy Photoshop. The savings off the normal MSRP are substantial. For example, Creation Engine offers the complete Adobe package - Photoshop, Illustrator, InDesign, Pagemaker, GoLive, and Acrobat - for just $379. This is definitely a comparable, if not better value, than Paint Shop Pro.