hiw much would an original poster be worth now?

Back when the the Exorcist was playing in my local theater in Yonkers, NY. I had asked the girl that sold the tickets to keep the poster for me, when the movie stopped playing in the theater. She gave me the poster, I took it home, but I still felt funny about keeping something that scared the hell out of me. I was 12 at the time and I didn’t want to keep the poster in my house. I ended up throwing it away. It was an original and I was wondering how much it would be worth now? In those days, they also had the lobby cards, but I didn’t get those from the theater. The theater doesn’t exist anymore, but I had wonderful memories there. That same theater showed all the exorcist rip-offs too. It was a grindhouse theater, showed all the kung-fu , blackploitaion, Godzilla movies, etc. I’m glad I got to experience the feeling of horror when watching the exorcist, actually, I hid under my jacket, so I only got to listen to the rest of the last 30 minutes of the movie. My stomach was tensed throughout the last minutes. Years later, I watched the movie on tv with my family, then later on video, then on dvd, now it doesn’t scare me like the first time. the kids of today would’ve been scared to death back in the 70’s, now they laugh at the exorcist, cause they are used to the freddy Kruegers and Micheal Myers, etc. Long live The Exorcist.