Thanks for these more constructive suggestions! (Yes I know that "value is subjective", but after all there is a whole valuation section here, so I guess I naively thought this was something people would discuss...)
So the overall opinion is that the trimming here basically made the poster worthless, or at most on par with the linenbacking cost? Well that is good to know. I think the poster still looks good enough and I am happy to have saved around $1800!
BTW the eBay high price / BIN suggestion is a good one, hadn't thought of that before!