Price- Well, I would have to say Gimp's price is way better. On Amazon, Photoshop CS5 Extended is $999(ouch.). On the Gimp website Gimp is free.
Ease of Use- Gimp definitely has a learning curve. Sorry, but so does Photoshop. But, the good news is that Photoshop has tutorials on how to use it. Personally I have not watched any of these tutorials because its was easy enough to switch from Gimp to Photoshop. I would say Photoshop and Gimp have about the same Ease of Use although Photoshop would be easier to start out using because of the tutorials.