I decided to give it a try so I took one of our boxes of old decks and went through about half of them, pulled all the rares and uncommons and then went through and listed them. I found one of the really valuable cards I'd remembered in the process and by the time I'd listed them all the collection was worth about £500, which made me decide to take the plunge and go the whole hog. Over the rest of the weekend, I sorted about 40% of the boxes and listed all the rares/uncommons I could easily identify and the collection is now worth about £2500, which is a significant chunk of a holiday if it actually sells. The big unknown at the moment is how much of it actually will sell. I did get one sale almost immediately but it was for a card that I realised afterwards I'd significantly underpriced so that's not necessarily an indication of how busy things will be but I guess I can only wait and see. If it goes well, there are lots of cards still in the boxes that might be worth something because they're from an era when the rares/uncommons weren't given gold and silver symbols to make them easier to spot but I'm probably not going to do that trawl through unless there's enough volume on the easy cards that it seems worthwhile. I'll probably finish the rest of the boxes over a few evenings in front of the TV though. On the off chance anyone on here is interested, you can see the collection here: https://lilianamarket.co.uk/tinyo
Something about the whole process of sorting and listing was rather hypnotic though and I ended up basically spending the whole weekend doing it rather than, say doing the gardening. Still, it is useful, at least in theory, so I guess that's not too bad.