Individual food items can become hideously expensive, of course, particularly if it is of very good quality and very rare. For instance, maple syrup is very expensive here in Brazil.
I don't know whether that applies to this specific turkey, but it seems to me that it is only a problem (and a very big problem at that) if this situation is at all representative of British food prices in general. As long as affordable food is available, all should be ok.
Granted, to the best of my understanding food prices have been rising alarmingly pretty much everywhere. But it better not be to that degree!