15 million in funding for 1 million processors? So every processor cost only 15£? That sounds pretty good to me.
So, 18 cores per chip. 55,556 chips. £270 per chip.
Still pretty good, considering the £15M is paying for more than a pile of chips.
[1] http://apt.cs.manchester.ac.uk/projects/SpiNNaker/SpiNNchip/