Take this with a huge grain of salt, as I have attended neither program, but I have spent 15 years working in media fields in Los Angeles and have heard a lot of anecdotal takes on this. My understanding is that they are both good programs and would provide a high-quality MFA education. If you fancy yourself more of a super-driven, self-starting type with your sights set on Hollywood success, you might gain more from a USC type program and the network and name recognition it offers. If you are looking for more support, perhaps a more collaborative atmosphere, LMU could be a better choice. FWIW, I know I wanted to learn first moreso than get that professional edge, so I skipped AFI and USC altogether in my application process. My career experience has seemed to suggest that the work you do at each level is far more important in creating professional opportunities than any degree you might have received.
The money question is one that is very individually tailored, but as someone who did get into a LOT of undergrad debt, I think it matters. The difference between $120k and $40k in loans will feel a lot different in 5 years than it does now. I did feel like there were a lot of opportunities that I passed up because I was desperately trying to make enough money to stay afloat in Los Angeles (a city that's only getting more and more expensive). HOWEVER, the real question is how much are you going to feel that extra $80k? It's different for everybody, and if you have the support system to shoulder it and still be able to spend years taking low-paying gigs that may be great opportunities to learn or build connections, then I say go wherever you think you'll get the opportunities you value most. If that money is the difference between starving or living comfortably and without crippling financial anxiety, then I think that needs to factor into your long term plan re: taking on debt.
