Step one - visit
Apple's website and find AppleStore locations around Los Angeles - a map of LA with names of suburbs would be useful!
Step two - work out which ones your relative can easily visit (largely depends whether a car is available, otherwise it's public buses).
Step three - the Apple site also gives directions to stores - print these maps out.
Step four - when your relative arrives in LA, get them to ring each AppleStore (around opening time) and try to find out if they have "refreshed" PowerBooks in store. Don't use the word "refurbished"!
Step five - if a store has the PowerBook model you want at the right price, get out there immediately and check it out. If you don't find any, try again in a day or two.
Step six - insist on seeing the refreshed PowerBook power on so you can check the screen for dead pixels.
Step seven - if happy with the PowerBook, then buy it. If you can afford it, also buy AppleCare - it's cheaper to buy in USA and is global in coverage.
Step eight - it's up to you whether to declare the laptop at customs. You have more chance of convincing it's your work/travel laptop if you have it in your carry-on luggage, separate from the PowerBook box/packaging in your checked-in luggage.
Good luck!