I would suggest you do your must-sees in Arizona on this trip. It's closer geographically. Otherwise you'll be spending a valuable day to travel to Oregon/Washington. Save that trip for later and combine it with other Pacific Northwest sights.
Las Vegas. You can make just a quick stop to see the lights and glitter, catch dinner in a swanky casino, play a hand of blackjack, and be on your way.
If you do want to spend an extra night before heading to Los Angeles, go way west, and head to San Luis Obispo and spend a night somewhere near the coast.
Stay in timeshares versus hotels. Save the money you spend on eating out for other things.
PS. National Park lifetime passes are $10 if you're 62 or over.