interesting its number 17 in the top 500 list. I would wager that the government here in the uk has a couple bigger ones that they can't talk about. I bet the US has a few too.
The Top500 list refers to performance on the linpack benchmark. While the UK and US government probably have "more powerful" systems than this which are used for classified purposes, those are likely to be special-purpose designs which aren't able to run the linpack benchmark. (For example, the NSA has access to wafer fabrication facilities, and is believed to have several custom silicon designs.)
The linpack benchmark runs on general-purpose supercomputers, and non-classified supercomputers shared between a large number of researchers are inherently general-purpose supercomputers.
59.4 M / 12000 = GBP4,950 each. A good desktop computer is less than GBP1,000. It doesn't sound like a great buy.