Well, the price that was quoted was $50/each way, and will be higher if there is traffic. A car would be a lot cheaper, but if you came by taxi you wouldn't be worried about trying to find your way if you are not familiar with the area. You will only be on one highway, I5, so it is pretty much a straight shot, so if it was me I would probably get a car, just to have the ability to go see more things while you are here. San Diego is a cool place with lot's of things to do. Pacific Beach, La Jolla, Golf, Food, and then you can always come north to Laguna Beach, Monarch Beach, as it is very cool here as well.