So $12 for parking that is normally free? Just for the privilege of a guarantee?
I also drive late and park for a few hours sleep, but avoid the truck stops. I avoid truck stops, preferring rest stops, pull-outs, or parking lots. To be honest, I park wherever I want that feels safe. Don't even worry about postings much. Worst case I get woke up and asked to move. I'm going to be getting up anyway. Hasn't happened yet, but it could happen. No big deal.
So if you like truck stops, the $12 might be worth it to you. You might also get more creative in your parking options.
2006 F250 Diesel
2011 Keystone Cougar 278RKSWE Fiver