there used to be a lad on here called pig-boy or somthing like that.
he used to sell half pigs, he'd even get some of the off cuts converted to sausage as part of the deal.
whether or not you'll save depends on how much you pay to start with, but as a general rule yes, buying in bulk on meat works out cheaper.
if you do buy from an independant or direct from a farmer that deals local / organic, the differance in quality versus supermarket mass reared pork is worth the effort, it really is a different class.
if you do a search in the classifieds, for half pig you may find the thread with a