I have PSP8 but I have heard from many many people PSP7 is loads better.. and I've also had someone recomend PS to me.. I can't find 'em!
Try to get an edu. version of PhotoShop 7 cheap somewhere, like a college bookstore, or on an education website where they have their online libraries. That's what I do with all my software, and it's completely legal, and the software works just like something the industry professionals use.