Earlier in the year I purchased a copy of "A Caravan Afloat" by C J Aubertin. It was a first edition - published in 1916. The book was recently featured in an excellent Waterways World article and is a true classic of early pleasure boating.
I found a single copy in the UK using the ABE Books web site but when I came to pay the £75 (yes it is rare and I am a keen collector), the seller couldn't find it in his shop. It appeared that when he moved premises he misplaced it. I eventually found a copy in New Zealand using the Alibris web site. It is an excellent copy in good condition and it was around half the price of the UK book.
Recently I have been monitoring a copy that is for sale on Ebay. At the moment it has no bids with just two days to go. With a reserve of around £29 it will be interesting to see what happens. I wonder if there will be a last minute bidding war. I won't be bidding!