I collect (buy/sell/trade) lots of vinyl and I am always running into pieces that are tough to find any info on. I do the usual searches (ebay, gemm, popsike, coll. frenzy) and have Manship's book, but there are still many pieces that I cannot find info on. What do you think is the best way to determine a price on a piece that seems to be undocumented? Any help or tips would be appreciated...