Why would you pirate it. Lol. The only differences between the free one and the paid one is that you can export the game to different playable systems, and you get better shaders along with a few small time things, like better water... Nothing special.
You can get plenty of free textures like tree's and floor textures, and even free buildings and models that you can use in any of your games you make from the unity store (in the program, not on the website)
I mean, if you REALLY want to be able to export to different playable systems via pirating the full version, dont expect to be able to sell your products (obviously) and just have another computer with the free version on it (or same pc, w/e)