By triangle I assume SF, LV and LA? I just returned from such a trip. My friend and I also didnt drive. We didnt follow the local tour company because we dont like the itinerary. We took Southwest Airlines to travel between SF-LV and LV-LA. We got the tickets when Southwest had a promotion and each way was USD49 only. LA we actually stayed at Anaheim so that is nearer to Disneyland. Can use John Wayne Airport at Orange County instead of LAX when flying domestic from Vegas.
In SF, we joined day tour to Monterey/Carmel, as well as city tour/Muir Woods. The rest of the days we just travel by cable car and bus around SF. LV we joined day tour to Grand Canyon South Rim. Stayed at the Mirage and walked along the strip. LA we joined city and Warner Bros tour as well as a tour to Desert Hill Outlet. Overall, the day tours average about USD100 each. The Desert Hill Outlet transportation is cheaper around USD50.
In the end, the cost is just slightly cheaper than a tour by a local agency. We spent around $4000 per pax for hotel, food, 3 steak dinners, Vegas show, night inside South Rim and all the day tours for a 12 night stay at West Coast. Definitely more expensive than self-drive, but we got picked up and dropped off at our hotel for all the day tours. And, it saved us from driving for hours and getting stuck in traffic jams.