Its unclear who is paying for them, doubt its the council, as they are pretty bankrupt, so possibly the police? Maybe a camera is cheaper than a traffic officer?
(revenue goes directly to central government, to revenue isn't part of the who-pays-for-them debate)
Its been on Radio 2 all day about this. Thames Valley are covering the cost to get it up and running. £600,000 for just this year!
They said 8 people (iirc) have died in RTA's since they were turned off, yet (only) 2 were in a speed camera zone!!
I would prefer to see more traffic police out & about than these bloody cameras. I have more respect for a patrolling traffic car than these money boxes. IMHO 
Local TV news says the council were paying £600k, but TVP will be coughing up £800k to run the 72 cameras in the county, paid for by £35 from the awareness courses when caught.
Although they have publically claimed that they have local proof that speed cameras saves lives, when forcing the point, TVP admit that the results from this episode is inconclusive, and they are fudging some
specific national results.
The 2 camareas they left on for statistic reasons were the ones where the speed limit is deemed controversial. The fact speeding increased at one of those sites shows, to me, that the speed limit is inappropriate. Knowing the site, I think it should be a 40mph. The figures do not say what the thresholds were set to on the camera, or indeed if it was the same when it was 'live'

£800k is an awful lot of money. I personally think that could be better spent on more officiers (and I don't mean the camera partnership part-timers), and also teaching schoolkids the Green Cross Code, the latter I believe would dramatically reduce accidents.