Ok, here's the run down:
La Jolla is quite isolated from greater San Diego and probably has the highest living cost. You won't find a 1-bed apartment near the school for under $1000 and rent can run up to over $2000 for 2-bed or 3-bed, depending on the season you start your lease.
Probably ~1400-1950 in UTC for a 2 bedroom. The school is basically in UTC and not the actual heart of La Jolla. 3 bedrooms might cost 2000-2700 depending on which condo/apartment complex you pick.
However, I find that the reduced rent from living farther away is not worth the morning commute, unless you're really a morning person. Parking cost over $600 a year for grad/professional student and you may still have trouble finding a spot in the morning.
The drive from Del Mar enters the 5 and exits straight off the 5 to UCSD with it's own lane. You won't find much traffic that way but rents in Del Mar are fairly high. Any other place (south of campus on the 5 or 805) will probably result in traffic. Parking isn't bad at certain structures but those are the ones farthest away from the Pharmacy school. There's almost an entire structure devoted to grad student parking but it's smack dab near all the undergrad housing (which is why it's empty most of the time).
Your best bet is probably finding student housing or find some roommates on craigslist/facebook and take advantage of our good free public transportation system. Several bus routes are free if you get this sticker from the parking office. We also have free shuttle services for areas surrounding the school which is what I usually take.
Yes get the bus sticker. If you decide to commute, you can still park at UTC mall, Nobel, Arriba, anywhere really ... and take the buses in for free.
UCSD is HUGE, by the way, which is why I understand they did not have a tour for the interview. Even if you opt for the on-campus/student housing, it might still take you 15-30min walking from on-campus grad housing to the pharm school, since the new med/pharm/grad housing building isn't finished yet. There's a shuttle route called the Campus Loop just for going around the campus itself because it's so big! If you choose grad housing in adjacent communities, they have a pretty good shuttle system dedicated for that. You probably won't want to walk from there since you'll be walking across the 5. But then again, some people do.
Chances are you won't stray far from the Med part of campus... There's a hole in the fence by one of the grad housing areas where you can take a shortcut if you wanted to walk. It's still a bit of a walk but not that bad.
Here're some links you might find useful:
http://www.ucsd.edu/current-students/student-life/parking-and-transportation/index.html
http://blink.ucsd.edu/facilities/transportation/shuttles/index.html (I swear by it)
http://hdh.ucsd.edu/arch/gradhousing.html
In addition, there are many large apartment complexes in the area you can explore but you might want to look up some reviews because some of the management can be rather unpleasant. Again, rent is expensive. Run a google search for La Jolla apartments and see what comes up. Most complexes won't pay for water and garbage either, so be sure to ask.
Hope this helps!