While we're on the subject of auctions don't all for any of the pathetic fakes that continually crop up at "reputable" auction houses. This one just sold at Raffan Kelaher & Thomas in Australia "attributed to Ronald Searle".
To the keen eye of a Searle enthusiast the weak, unstructured drawings belie their amateur forgery. Searle's style was loose and vital but never sloppy. His finished works were worked up from numerous rough sketches and had elegant compositions.
I've tried to alert a well-known British auction house in the past who were oblivious to selling a fake Searle but rebuffed my accusation affronted that their "expert knowledge" was called into question. Which instantly made them into Searle-esque stuffy, art dealer snobs!
Sometimes these fakes will pop up on eBay too with the "attributed to Ronald Searle" or "after Ronald Searle" but don't fall for it.
More fake Searles here and here