the only way to play GTA is to upgrade. but if i were you, i would consider not upgrading because, if you did buy a virgin 1.5 psp, you might be able to use custom firmwares.
i doubt that any are in the works right now, but its still a possibility. one that you might wanna consider before blowing the chance away forever by changing firmwares.
Many thanks for your help!!!
Yeah..searching these forums...
There is a thread that contains all firmware eboots (including 2.0), a thread that contains downgrading instructions, and that is all you need