Why do you find it necessary to exaggerate? What was this "upgraded" keyboard and mouse from Apple? The Apple keyboard and Mouse that came with the Mac you claim was the same they sold on their website and stores. Keyboard price was about $49. The Mouse was usually about $29. If you wanted a bluetooth wireless mouse (I am not sure they offered them for the G4 PowerMac because it was not offered as a factory installed option). Then you MIGHT have gotten to a $120 bluetooth keyboard and mouse including a Bluetooth USB adaptor.
Did you buy this G4 used? Or new?
Or you could have unplugged the keyboard and mouse that you liked from your PC and plugged them into your Mac. The G4 supported standard USB keyboards and mice. Next to my keyboard as I type this is a Microsoft Intellimouse Explorer, an ancient mouse that I keep because I'm used to where the forward and back buttons are.
Oh yeah and their LCD screens are no sharper or brighter than those built by LG or or most other manufacturers...only 2-3 times as expensive...no better.
They have much better design and color correction. All the adjustments are in software -- no front-panel buttons or menus. If that's important enough to you to justify the price, then go for it. If not, just plug in that LG. I'm looking at a 20" Dell LCD, which used to be connected to my G4, as I type this.
No question, Apple peripherals and upgrades are pricey. That's a fair criticism of the devices, but not of the platform; there is nothing locking Mac users into Apple displays, monitors, keyboards or mice.