Yes, the tuition here is absurdly high and honestly, I have no clue why that is the case. Our tuition for next year was a 4.7% or 4.17% (I dont remember the exact numbers) increase. The % hike isn't the issue, it's the base cost of this school as all schools will have to adjust for "inflation." Our class jokes around that the ~4% hike goes to the real important things like air conditioning and water for the stiff grass. Not for internet cause no one needs internet in school.
If you got another acceptance and got good vibes from the other school, there is no harm turning down this acceptance. But if this is your only acceptance then I would think twice before rejecting this acceptance. An expensive school is better than no school.
If it makes you feel better, there has been 1000+ grads from AZCOM and most of them made it out fine despite our ~300K debt.
Rotations during MS1 doesnt matter as you will get to switch later approaching 2nd year. PHX definitely has more spots but in terms of strength, there really isnt that big of a difference. The only plus that PHX sites have over all the other places is home court advantage.
E: I should add that it may be easier to switch from LA to PHX than vice-versa.
I don't think board scores have anything to do with choosing a rotation site.