I dont know about it being valued at £200+ but it is a well sought after book by a lot of pigeon fanciers and will most likely fetch a lot more than you paid for it. The last one I seen for sale on ebay fetched over £80.
I have my older hens out of the loft now that the weather is improving but they have not seen a basket yet. My older cocks only have had 5 tosses out to 30mls.