Welcome to the world of Thomas OO Gauge World, there are some nice bargains to be had at the moment on second hand Hornby models. Although to be fair some are selling at absolutely eye watering prices, for example i recently saw some examples of the Hornby Stepney loco (genuine Hornby release based on the Terrier model) which seem to be in the £250-300 price range. As for the Murdoch I saw that was just silly money lol!
Happily collecting things all my life... 