Free: Contests & Raffles.
There are lots of places to hunt. Do you really need to go climb into this blind that they've taken the time, effort, and money to build? Sure, letter of the law says it's legal. Because something's legal doesn't mean it's right. I'd find my own spot. My Wile E.
If you use natural material your fine. If you bring in boards and tarps, etc. It's actually illegal to construct a permanent fixture on state land. They can come in and tear it down as well. It's still done frequently. When you head down to the gulf of Texas and Louisiana you see them all over on the various little islands. If it's a good hunting spot with lots of birds I would use it as well. I have had guys build crappy ones in spots that we hunt consistently and those usually end up getting pulled out. If your going to spend the time to do it, do it right or don't build one at all.
I knew a guide that built wire blinds with a nice 2x8 seat on the way to his spot.... That way no one would walk farther to get to where the actions was.... He was the only Part time Tenured Professor at CWU