hmmmm, sold a classical lp on fleabay the other day for 160 quid, probably picked up in a junk shop, Mozart Symphony #32 SXL 2135. I found an obscure folk lp in a charity shop that sold for nearly £200 but I gave a chunk back to the charity, 1st press Dark Side of the Moon went for £100, wrecked copy of Pink Moon went for £100, they turn up occasionally.
I am sure there are a few others, some I have not sold on as I keep them to listen to even if they are valuable sometimes
My brother makes his living selling vinyl he gets from junk shops etc, I think he recently found a reggae single that is valued at £1500 !! These things turn up, so keep scouring the junk boxes.