Wanted to let you guys know that someone on Amazon has these posters for $10. They are in mint condition and yes, they are from when the original movie first came out. I bought one and framed it so you could see that it was legit: http://www.amazon.com/Jurassic-Park-Poster-Dwellers/dp/B001O8P728/ref=sr_1_5?ie=UTF8&qid=1381271723&sr=8-5&keywords=jurassic+park+poster

Looks like he has a couple other posters as well.

EDIT: Looks like you guys went to work on that Amazon link because they're sold out.