What is a good hotel within walking distance of the beach in san diego that has a spa and is not too pricey?

I will be turning 17 and want to fly my best friend over here from north carolina to san diego for my birthday. I wanna spend the night at a hotel that's walking distance (literally) from the beach. Also I want to go to the spa with her so a hotel with a spa would be really nice. Buttt I dont want to spend over $180 for just the night. any suggestions???