British writer and producer Stephen Follows has a great blog that discusses the film industry, with a particular focus on the UK film industry. There are some great posts on there including one that breaks down the budget of a £1 million British indie film, Papadopoulos & Sons, including income up to the time that the post was written a few months ago.
In the Sound budget there is £16,882 for production sound, but post-production sound cost is not clear as there is a £66,801 Post Production Deal item which could include more than just audio post. There is also £25,507 in there for music costs.
Check out the full breakdown including some great info on indie film distribution at:
http://stephenfollows.com/the-full-costs-and-income-of-a-1million-indie-film/