Ive been looking at packages through Priceline.com and you do have to fly out of the states with that company, however if it is not an issue like me and I will fly out of Washington, you can find some really sick deals.
For 4 adults in one room, for 8 nights 9 days staying at the Del Sol inn, with taxes included for flight and hotel, it costs $389 per person. This is flying into SNA.
Flying from Canada into the States is much more expensive. The earlier you book, you can find some good deals. I would search different travel agents online and see what they are quoting. Were you planning to do San Diego at the end of your trip or at the beginning?