Thank you all for your valued comments. I had a look at Petris on ebay yesterday. One thing I do notice is that the price of RFs appears to be creeping upwards. A lot of dealers are asking £40+ for Yashicas, Minoltas, etc. Private sellers do not seem to be as high, and a lot of those do not know how the RF works, and do not have a battery for them, so they are sold as untested.