Wow, lots of places, but there is one place that could really do with a mention...Your Local open air Market, usually there you will find a meat auction lorry. We have one in Shrewsbury that is really fantastic.
For £5 you can get 13 chicken legs, 12 Pork Chops etc
All the meat is of an excellent quality and if you arrive later in the day you get the better deals.

I am sure any open air market across the country will have this type of stall!