I shouldn't reveal my sources really. But then this was an exceptional case and I don't expect it to be repeated any time soon. 99p. OK, plus £5 postage but still, 99p. Ebay. Expect to pay more. I could not believe my luck. 99p and with it not only did I get Volume 58 but I also completed the 1960s section of my collection. Probably the best era for Penrose…maybe the best era for the graphic arts in general (at least from an historical point of view).