Good idea.....PS3 was $599 because of Bluray. It read discs slower, and required many mandatory installs, where as the 360 version would require megabytes for game saves....
Aside from the occasional exclusive that actually took up most of the space, the vast majority of the generations games were on one disc for 360/PS3. Near the end 360 games had a "install" disk so there wasn't any disc swapping needed anyway (Halo 4 and GTA5 come to mind).