I've never tried cost justifying the usage of any of our campers or the expense of traveling somewhere or the cost of any campground. Bottom line, it's most cost effective to NOT have an RV at all, to NOT travel anywhere, to stay home, and sit in the dark.
But if we want some adventure in our life and can afford it, the cost is NOT a factor at all. It is a "life style". Consider it a hobby that consumes you full time. Any hobby you have makes no sense at all.
Sports? Do you attend any sporting events, even a grade school basket ball game. Does it make any sense at all? No. They play a game this week and win. For 7 days they are "winners". Now on day 8 they play again and loose. Now they are loosers for 7 days. Again and again. What's the purpose? What's the value? Why spend your money on such idiocracy. There is ALWAYS another game to be played. In the end, there really is no true "winners" becaue, eventually, they will loose a game. Does that make sense? No, but people enjoy sports with a die-hard passion and support their teams, win or loose. Can you justify the cost of supporting a loosing team and attending their games. No, absolutely not. What do you get out of it. You spend your money. You pay $15 for a paper cup of beer, $10 for a hot dog, and you sit in the sweltering heat or the frigid cold. You now get sick and have to go to the doctor the next day, which costs you $120 for a doctor visit, $30 for a prescription, and 3 days off work because you feel so bad. Cost effective? Absolutely not! Yet folks do it all the time! Why? Because they enjoy it!
That's why we do RVing. If you enjoy the campground, then go and just do it. It doesn't have to make sense, and you don't have to justify it. If you don't enjoy it any more, then stay in a motel. If you are loosing the passion for RVing, then IT REALLY IS OK TO CHANGE. It is!
Good luck. Just do what satisfies your soul. You don't have justify anything else.