Can anybody explain why they would bid (currently, about 15 hours to go yet) £117 for an old vinyl copy of Folk Roots New Routes when you can buy it in much better quality on a new CD for under £12 on Amazon?

Well, that's what record collectors do - especially if the vinyl is in mint condition. CDs, of course, don't always give better quality - much depends on the re-mastering. Early CDs were very harsh and tinny compared with the warmth of vinyl recording. When the CD became fashionable and swept all before it, record companies rushed to produce them and the re-mastering, in many cases, was abominable. The Beatles albums were a case in point. The only serious re-mastering of the Beatles in the history of their CDs was the recent "Love" album by George Martin - and it shows.

Vinyl is still the recording medium of choice for many people - Neil Young, I believe, has vinyl and CD versions of his new albums for sale. I love vinyl, myself, and still pick up the odd album here and there.