Even though the Assassin's Creed movie isn't coming out until December 21, you can get your tickets right now. Kernel, a website that offers "Curated offers on anticipated movies, games and events," has placed several bundles on sale on their site in anticipation of the Assassin's Creed movie.
Packages start at $15 for a movie ticket, collector's watch, temp tattoos, and a digital script, and go all the way up to $1,200. The highest priced package gets you a movie ticket, digital script, "behind-the-scenes extras", and a Spanish Crossbow that is an exact replica of one used in the movie. I'm not an expert in 15th-century European weaponry, but it looks like a pretty good crossbow.
I personally don't really understand the appeal of spending $1,200 for a movie ticket and a crossbow, especially when you can probably get a better crossbow for cheaper. Expecting someone to spend that much money on memorabilia from a movie that isn't even out seems a bit foolhardy to me.