I've offered to sell some unwanted books for my mother-in-law on e-bay. They are mainly hardback first editions.
I've checked the usual sites for valuations and e-bay of course but a lot of them are rare and not recently listed. The other sites show some of them for around £40/£60. I realise though this is just what the dealer hopes to get for them. How do I price them for e-bay? Should I take what they are listed for on other sites and take say £10.00 off. I realise these are not hugely valuable but for the sake of family harmony, I don't want to get this wrong.