The guy across the alley had half a dozen vehicles and a few trailers and no place to park them. 

We brought in a 20 yard dumpster and filled it up with cat-destroyed furniture and carpet, as well as a ton of trash - only to make multiple other trips to the dump with a 12 foot trailer.   

I think in my knowledge so far first problem here is you will need that renter to get approved from mobile home park, if there policy is that only owner can live in mobile home then you can not rent.I too am thinking about buying mobile home or travel trailer and then buy land to park it on.I my research so far South California is far more open to buying land and park travel trailer, mobile home on it?

Tell them to rent a trailer and borrow a friends truck because your new tenants are arriving on the 1st. with them there or not.  

It is predominantly  a few squatters, two illegal renters, and about 10 to 12 empty overgrown ancient trailers.  

Cost 16k includes trailer.

I owe $10,000.So without boring you with details... should I pay cash for a cheaper camper trailer, fix it up, and live in that?

I put in a septic system, a gravel driveway, brought in electricity, put in a well, did some fencing, lived in my Airstream trailer while doing this work on the property.  

From his address, it seems like a trailer park.

If the trailers are worn and in need of refurb, then the "market rent" wouldn't apply as the condition they're in wouldn't rent for that much.