What Reddog said plus the mental health aspect of not stressing by being able to go and come as you like to where you feel like being, that to me is priceless.
take visiting Yosemite. Ok if I stay in a tent it will still cost me the same campgound fee and entry fee as my TC or I can spend $150 to $500+ to stay at the Yosemite lodge or Ahwanhee hotels in the valley.
In the TC I am warm and comfortable, tent not so much
Hotels I always wonder did they wash the bed cover, bedding,and are there bedbugs or lice in the room. I know when I washed the TC linens and that there are no critters in the bedding
I also have no interest in driving 30 plus miles from the river, lake, or mountain pass at the end of a day of play to get to a hotel room...
I guess I am more focused on the return of fun on my cash outlay than a dollar return if I sell something.
Plus I earn over $10,000 each year working out of my TC as a weekend EMT which more than covered the TC purchase cost and truck expenses