It's defenitely worth the extra 30 than getting GT 3. If only just for all the new tracks and cars. GT 3 had about 20% of the cars that GT 4 will have. Then you add in the online play, all the new licensed (much better compared to other games licensed choices) music, atleast 6 new modes (drift, photo, flea market, bank, and travel agent). Better graphics, better physics, etc. And Polyphony has said they're interested in utilizing the PS2 harddrive, so getting new car downloads or tracks and more wouldn't be out of the question. There's probably alot more too, thats just off the top of my head.