In Mexico parks are cheap and if you plan to stay for awhile they have long term rates that are very cheap - we have seen $400 a month and less.
I am paying less than half that for a house.
But I will not boondock solo, one drunk or one punk with an old pistola or knife can ruin your vacation. Since I speak Spanish it is no sweat for me to make gracious arrangements with a family to park nearby overnight.
MOISHEH, Mex 200 is no more or less hazardous now than anywhere else in Mexico. I deal with folks who got robbed at gunpoint 20 miles south of Rosarito, BCS. San Quintin, Jalisco, Nayarit, and really risky places like Sinaloa, South Oaxaca, and Chiapas beaches. Most are tent campers.
The key is not isolating yourself. Befriend a family and park within shouting distance of their residence. Remember the incident in downtown Mazatlan where in the confines of a fenced RV park a rig was robbed at gunpoint and the owner was gunshot fighting with the robber? The robber came through a hole in the fence. The key word here was and is ISOLATION. Mexicokid was held up at gunpoint at a gasolinera in the middle of the night. He parked in pitched black isolation and did not bother to chat with any of the night crew at the station. ISOLATION strikes again.
Mex 200 is going to have a long life in the boogieman / chupacabra tales of fright in Mexico. More people (including Mexicans) get robbed on Mex 57-D in a week than have been robbed on Mex 200 the last 20-years.