Selling Rare Vintage Poster Collections

Level 1
Question for anyone with experience. I have a large collection of rock memorabilia/posters left over from my family’s record store that we owned from the early 70’s to mid 90’s. From my research, a lot of the posters are very rare and valuable selling on eBay individually for 100’s apiece ($110-600), specifically the posters from an artist named Roger Dean. I need to sell them ASAP and trying to sell the entire Lot at once. About 126 posters altogether. It’s worth at-least 4K, but I’m looking to get around 3K to sell them fast.

Is this realistic? Is OfferUp a good way to sell my vintage poster collection? And is this price range too high for this market place? Would it be better to break up the entire inventory into more specific collections, etc. ? Open to any tips, tricks, success stories, experience.

Level 1
Ok so there's a guy in California that will pay top dollar for good posters. I found him 2 years ago when I was selling a Janis poster. I think I just Googled "vintage music poster buyer" I think you could easily get 3k for what you're describing.