I just won this on eBay. On Amazon, it cost $77.53 used. I got it for GBP 4.20 (or $7.43) plus shipping.

The description reads:

Coleus – A Guide to Cultivation and Identification

– Published Edinburgh, John Bartholomew 1974
– 8vo with 116 pages, colour plates/illustrations.
– Book in very good condition, with slighly faded dust jacket .
– First edition signed by both Pedley brothers who were Lancashire nurserymen.
– A delightful little book covering every aspect of cultivation of this versatile plant.