I agree with Tony on this. Having previously worked for an Oxfam music/book shop, our main aim was to get as much money in TODAY for the charity and not in a year's time. The pricing of secondhand vinyl has become contentious, more so than the pricing of rare books which genuinely have to be rare on an Abe scale to be priced highly. Books also have a regional factor built in - ie Wainwright's sell for a greater premium up here than they might down in Cornwall.
It's different with vinyl, and I think most Oxfams now try and price records to the highest scale they can find on, say, Music Stack. Thus, I've seen a widely available average condition Joni album in Oxfam for £50! Noone is ever going to pay this, so far better to charge a fiver and get the money in right now - given that only a third (approx) of money over Oxfam's tills actually finds its way into 'the field.' Our local Oxfam is charging a tenner for some old Vardis albums. Did anyone ever listen to Vardis back then, let alone now? Again, charge something sensible and get the cash in, this instant, rather than hoping for the one punter in a million who might pay the ridiculous overcharge in ten years' time. There is no excuse for secondhand shops to have an abundance of back stock. Get it out, get a steady cutomer flow, and get the money to where it's most needed.