I purchased some Nancy Drew books recently, including two copies of the Nancy Drew book, The Mystery at Lilac Inn. Since I had two copies of this book right in front of me, I immediately noticed that one of them has a purple tint to the cover. I had never seen this before.
The book on the left has the normal illustration, and the book on the right has the purple tint. The book with the purple tint lists to Crooked Banister on the back cover. The inside lists
Nancy Drew to 99 Steps and Dana Girls to Silver Dolphin. The book meets
the points for the 1971A-100 printing according to Farah's 12th
One collector reported that he has two of the books with the purple tint and recalls having a third years ago. The two books currently in this collector's possession list to the same titles as mine. Another collector reported having seen the purple version. Since we have had several of these books spotted, we can conclude that a number of them exist. Since we know of at least three copies that have the same points, then we can also conclude that at least a partial print run has the purple tint. This means that more of them are out there.
I find the purple tint to be quite attractive. While I have always loved this book's cover art, I like the purple version even better. I'm not sure if this is more due to the novelty or because the purple tint does indeed make the cover more attractive. I tend to think that the latter is true. When I placed a scan of this book on my Facebook page, at least four people stated that they like the purple version better, so I'm not the only one.
Farah's Guide gives the 1971A-100 print run a value of $5.00. Since collectors seem to like the purple version, the value of the purple book would most likely be higher than $5.00, perhaps around $10.00.