You are suffering "paralysis by analysis"...let go of all the numbers for a minute and think about what you really want to do.
Do you want to travel? Take a train, take a plane, take an automobile or embrace the RV lifestyle. Not having owned one or lived in one will tend to color your perception of what that really means.
RV'ing is a lifestyle regardless of whether it is a full-time endeavor, a part time pass time or the weekend warrior warrior approach. It has it's own ups and downs. No one does it to save money or limit depreciation. They do it to have fun and enjoy the experience.
Do you want to live in NM? Then buy some cheap land and build.
You can't avoid depreciation and, if you buy smart on the used market, then you avoid a significant amount of the depreciation you keep throwing into your equations.
The outdoors is right there outside the doors of your RV. Living in a 300 sq ft fifth wheel for one person is solitude in a cozy environment.
But stop with the analysis and make a decision. Regardless of which unit type you buy, and I think you'd be amazed at how well a pickup that can handle a good sized 5'vr drives, if you are going to do this, then do it.