Wait, now I'm confused...
The two computers...
1) Powerbook 12", rev. A, 867MHz (
this model)
2) iBook G4 / 12" 1.2 GHz (
this model), or iBook G4 / 14" 1.2GHz (
this model)?
It would help if you could please be more specific about which PBs and iBooks you're talking about. Also whether each one has an Airport card and if the iBooks have bluetooth.
Unless the configurations are atypical (large or fast replacement hard drives, differences in how much RAM, etc), it would be unusual for that particular PB to fetch $200 more than the 12" 1.2GHz.... Later PB 12"-ers, sure, but not that one. That powerbook with the GeForce 420 is pretty ANCIENT.
It is probably worth noting that none of those three models support CoreImage in hardware. You need to go to at least a rev. B Powerbook or else the last revision of the iBook G4s to get that. But particularly that 12" / 1.2GHz iBook would most likely have no problems with Leopard if you put in the maximum permissible amount of memory.