This is a funny comment because just last week I bought a second-hand copy in Berwick-upon-Tweed. I haven't read it yet but it's been on my list forever and it's a mint copy with a nice yellow cover. It was published in the UK as part of the "SF Masterworks" series which is a trove of previously out of print stuff. If you come to London again you should find it in most large bookshops like Waterstones.