I think it is fair to say that the bottom has fallen out of the pigs-at-auction market.
I know that our nearest market (melton mowbray) used to have pig auctions once per month - take a look at their most recent report here : http://www.meltonmowbraymarket.co.uk/images/reports/MARKET%20REPORT%2015th%20JANUARY%202013.pdf at which "Fat Pigs" peaked at £100 and coloured weaners were selling for £21 at most.
Thanks
last week was a very poor turn out so prices were a little above the norm.
rule of thumb coloured pigs dont sell well. fat pigs dont sell well either. what is in demand is good well done white pigs (sorry but it seems to be the norm at markets around here)
we have melton, thrapston & newark around here they all sell pigs but dont always publish prices.
best advice is to visit a market before you want to sell to get the feel of things and see for yourself how prices vary.
have a look on the melton market reports to see some of the prices over the last few months.
i have seen saddleback weaners sell for £5, osb x £3 berkshires £12 but at the same auctions welsh & other whites £35 -£45.
if your fattening pigs best sell the finished product or you could be onto a looser.