WELCOME ABOARD!!! I have never known him to sell bootlegs before and personally would not worry too much about him on them.
As to the posters themselves I will only speak to the Star Wars A & C.
Star Wars Style A, it is the relatively common record poster. They can be found fairly often and in very nice condition if you have patience to wait a bit. Average pricing ranges pretty greatly but high grade rolled examples generally run in the $200 - $400 range. The higher price being auction house prices. There is currently no bootleg of this one to the best of my knowledge and they do appear for sale pretty often but for some reason usually in lesser shape than other printings of the Style A posters, hence the patience part. When they do appear in nice shape on Ebay they usually run in the $200-$250 range but like all SW poster prices these days can swing wildly from day to day depending on who is bidding.
Star Wars Style C. The poster is the more common non PG version. Price after linen backing is not too terribly high, they average linen backed in very good condition, prior to backing, in the $1,000 - $1,400 range. These can be found both rolled and folded, this one was folded prior to backing but looks pretty good from the images. I would venture a guess that 90% of the C's that you see for sale on Fleabay these days are either legitimate reprints, usually 24x36 or 27x40 instead of 27x41, or they are the common "Hairy Back" bootleg. This one is an original based on the images. Original Style C's outside of sellers like Miniver and Cinemasterpeices, who both charge a premium for their wares often having bought them at auction themselves and reselling online, do not show up often but do from time to time. To get one in the lower end of the price range can take quite while or you can try the auction houses which see them every few months or so and average less in price.