I live in Newburgh, just outside Evansville. I'm guessing you are talking about the LBL. Rates here are about $60-$70 uncovered. I was offered a covered spot in a somewhat classy place close to the East Side Walmart, but I wouldn't pay $105. If it had been $95, I would have.
A wash station would be a big attraction for me. I'd pay $10.
I tend to agree that a dump station should be 'free' for people paying storage. I doubt that I would pay to use it.
If you got a reputation for break-ins, I'd be out of there.