But (as you know) it doesn’t quite work like that. The £1 book might never sell at £150, but that’s ok as long as you have shed-loads of similar books.
When you buy a £1 book hoping for a £150 return do you not bother with other books that you could buy at the same time that you could probably sell quite quickly (in the world of books quite quickly might be a few months) and make a substantial return on capital invested just because it falls below an arbitrary sales threshold of say £10? *
It’'d be as if if strolled past past free cash on the pavement, because I couldn’t be ars** to reach down and pick it up
(* a rhetorical question)