I'm not one to defend Mr Oldham as he does this very well for himself but it is his living and pensiion top up similar to myself - I reckon a fair valuation and trade offer for sought after volumes could be up to 50/60% of the volume if buying one offs that are turned back into cash reasonably quickly. You have to remember it ties up cash there are overheads in selling and buying - card charges, service charges (fleabay) envelopes /packaging However what often happens you are offered a collection and you will be sure to be offered numerous copies of descent, caves and caving, bcra poublications, cave science and numerous other books of low value - often seen on my stand at Hidden Earth T ?2 - ?4.
We also end up with some rare and obscure publications - if you can understand French / German/ Spanish/ Slovakian etc have a look
www.moorebooks.co.uk but these don't sell overnight and will hang around for months / years till someone unlocks the treasure chest.
Yes offering a fiver is demeaning but maybe ?10 - ?15 is realistic, depending on condition, rarity, quantity and demand
Mike
Mike