FF12 isnt as rare sealed, but I think that RE4 is in the USD $200 range in sealed/new condition. The good RE2 and 3, as well as CVX are sealed as well.
Haha! I keep unpacking a lot of old stuff from boxes that have been in storage for ten-plus years. My PS2 and GC both had controllers, mem cards and RE4 in the GC still. Will fire it up and see where I left off a decade ago.