For years, I looked in used book stores for a favourite children's storybook. My sibling had taken the copy we all shared when we were younger. With the advent of ebay, alibris etc., I looked on-line, only to discover it was considered a collectible, and prices were often over $100. I just couldn't justify it for a book that was probably in poor condition (as well-loved children's books often are).
Last year, on a dreary Saturday, waiting for an appointment, I was killing time in the Rozelle market in Sydney. The vendors have tables full of vintage clothes, antiques, and flea market stuff. I looked down - and there it was! My childhood favourite! For $5.00 (Australian, no less - so it was a really good deal!). I didn't let go of it for hours, LOL!