I bought & sold the standee lenticular to Holiday 2-3 years ago. just the poster part, not the whole standee.
it's rare enough, but the 1sh size Wattsy is looking for.. well the math is simple... 'try to find one'
when you're up in that rarified air, people can ask whatever they want to.
keep in mind, Harry Potter, because it it ceased being a 'continuous property' because JK Rowling wanted a specific end, the posters have stalled somewhat.
If it had been a continuing product, like Star Wars, I suggest the audience would be larger, and prices higher.
the $5700 (at current exchange rate) that the owner is asking could possibly be your only opportunity to get the poster if you want it that much and if he sells it to someone else first - you're probably out-of-luck.. forever!
as to Bladerunner rolled 1sh.. my warehouse email is warehouse@comic-art.com
message me and I'll see about one in my vault