I do believe I picked up a brand new digital projector not too many years ago, and the charge from the online retailer was about 30 quid.
So why do they say tens of thousands?
First of all, there's the significant issue of the massive amount of power and performance that's required from a theatre-class professional projector, rather than the comparatively tiny distance-throw, dimness, and short lifespan of a home or office HD projector. Quality, as a few have pointed out here, is a big factor. Also, to be that bright, these don't use LEDs of course: they use very hot bulbs that need to be cooled down with very loud and large fans and cooling systems.
Secondly, we're not just talking about the projectors themselves. Most of the major film distributors will not longer be providing films on actual 35mm film, which is what the drive-ins have been using. The major distributors have been reducing the number of "films" that are actually released on film; for some, the move to digital cinema is arguably more about the distribution methods than the viewer's experience. DCP (Digital Cinema Package) [wikipedia] —boiled down to MPEG-4 on an encrypted harddrive — is how the films are being sent to theatres. What do you need in order in the industry to run the required DCP drives? You need a server that will decrypt, store, queue, and run everything: trailers, all the films for the week, your preshow, etc.
The end result is having to buy a very expensive, closet-sized projector and computer server that your projectionists need to be trained on how to use and you can't fix yourself.
As someone who works for a non-profit film cinématheque, this is a very big deal and worry for independent cinema, who, without access to DCP projectors, are increasingly relying on having to present theatre-class events from a Blu-ray burned in the distributor's office.
See here for more info about the market changes from 35mm to DCP in this reposted press release [isuppli.com].
