Is it a really movie car or a clone of the care? I'd say it really depends on how important that movie pedigree is to you and how well its document trail is. I'd expect it to have very clear documents to tie it in to the movie as proof of its involvement. Title transfers, insurance papers, vin tracking or some other concrete evidence above and beyond heresay that someone say it was there and I snagged a copy of the script to throw in the deal. But the clone in your description is a big flag to me. Cloned at what point? For the movie, by a fan of the movie, by someone who just had a script?
A very clean, white R/T Challenger could easily be found for a lot less than that price to duplicate the same scene at your drive in. While on display, all you have to do is add one or two words to a display card that 90% of the poeple will never notice to create the perception it was a movie car. IMO, if this was not a genuine movie car awith document trail and you aren't too concerned with the script, it is not worth the money. History and documents are how these cars gain significant value over simply being a collection of parts.