prices really just depends on you. and all the other things really just depends on your liking.
its whatever how much you are willing to pay for a laptop. (i.e. the brand, the materials, weight, size, etc.)
all those other things will factor into what you want as your ideal laptop. and the above... like i said
atleast 512mb
60-100gb hdd
nvidia/ati video driver (this is what i meant in my first post)
you can get a Pentium M. if not, a P4 or AMD will do just fine. they will probably give u a little bit more power.
as far as everything else like cd/dvd, size, weight, etc... those are just factors you should decide on your own. for imaging, i might say atleast a 17"
and i highly recommend a tablet laptop. it makes graphic designing just much simpler. I am a graphic designer minor myself.