We mostly use Passport America and on occasion Good Sam. We also use casinos, some fairgrounds, Cabela's, city & county parks. There are 2 books by Don Wright, Free Campgrounds, Western & Eastern edition (Amazon). Nick Russell, who writes the Gypsy Journal also has publications about lower cost camping, like the Elks,
www.gypsyjournal.net.,
www.casinocamper.com. If you are a senior with the federal pass you can stay at Corps of Engineer campgrounds for half price, usually have water & elec with dump onsite.