Southwest is awesome to fly to San Diego--free bags, and they have a pretty good schedule to SAN.
I have found that there is a "sweet spot" on their fares which is about 30 days prior. Any more, and the fares seem higher, less than 30 can be OK to about 15 days, then they go up again.
For example, in looking at MDW-SAN now for June 14 arrival and June 18 departure, the fare is $431.60--only $55 less than I got last week for my March trip (12 day advance). We are clearly not in the sweet spot yet (plus fuel prices have spiked, so maybe that is nullifying some of the savings).
I am going to book that trip in early May, and expect a fare of about $345 (again, from Chicago).
The two hotels I like the best for that trip are the LaQuinta or the Ramada on Bonita Road and the 805 freeway.
The ramada is about $60 a night, including free Internet, which suits me just fine. Neither are BY ANY MEANS "luxurious." But "acceptable" for a BMX stay. If I wanted to stay "proper," I'd be at the Loews Coronado Bay or the Lodge at Torrey Pines, $187 or $365 a night, respectively (but way-far from the track).
I like the Bonita Rd. hotels for conveneince to both the track and the hotel, and because they have free Internet that's reliable. The LaQuinta has a better breakfast bar than the Ramada, but there is a Dennys right across the parking lot, so that's an option, if you are inclined to eat at a place like that (I was, for my first three trips, but now that I am a veggie, they don't really serve anything I can eat).
Bonita road hotels are about 20 mins from the track, and about 25-30 mins from the airport (no traffic), plus a Starbucks on the way to the track (via Telegraph Canyon Road), which is a major bonus for me! I am a huge creature of habit, so it just may be my OCD that likes Bonita road location, because of the familiarity and proximity to places I frequent when i go there...but lots of BMXers stay there...saw Mariana Pajon in the Elevator a time or two, which is always quite pleasant.
There is a Costco, and Wal-Mart near the track, and I always stock up on bottled water and fruit/snacks for the stay and race days as my first order of business when I hit town. Also a Trader Joe's on the way from the track to the Hotel--also a huge bonus which I hit a few times on a four day stay.
Hope these tidbits help. Feel free to reply with any follow-up questions. Hope to see you there.
P.S. Don't forget that the June Chula Race features both the US Olympic Trials and the National BMX Hall Of Fame induction ceremony. Be sure you're in the right place at the right time for both of those.