i am more than happy with my rg 570, it is one of the first versions with non aanj, i payed 175 for it with a prestige case. I love it to death, it is the best guitar i have ever got, i have an ibanez usrg30 which is nice but i like the 570 a little more.
Having never played a jem either, i couldn't compare the rgs i have to it, but i can say that the usrg30 with a lo-pro and the 570 with the edge are much higher quality than the lower end rgs. The neck is another important factor, the 570 has the wizard and the usrg30 has a special neck, it is a mm or two thicker than the wizard but it still beats the hell out of the wizard II which is not to my liking. Ibanez is kind of stupid for doing away with the wizard but i guess if they put the neck that everybody wants on higher dollor gutiars they make more money. So i figure that the jem neck isn't too much different from a wizard, and that most of the higher end models all have necks simular to the ones on my guitars.
175 and 500 for my guitars as compared to 2000, i dont think i will look to buy a jem ever not as long as i have what i have.