I agree with the theory, but if you think that the numpties who agreed to the ridiculously-priced purchasing deals the last govt used are different to the numpties overseeing the probably-still-ridiculously-priced purchasing deals the current government have in place, you're deluded.
The problem here is that government insists it knows what it's doing, but both NuLabour and the Tories have this hilarious notion that the Private Sector Knows Best and instead of bringing in people and expertise in-house to leverage savings over time, they bring in expensive contractors or "advisors" in the short term who sell them the kind of bullshit that only a total novice would believe. They then get "forced" to sign a 5-year/10-year/in-perpetuity agreement, and it's only when the invoices start rolling in that someone realises just how badly they've been shafted.
Of course, these are the same people who sold in-perpetuity spectrum exploitation licences with no restrictions on foreign reselling, and who've allowed most UK utility providers to be privatised such that the profits from them trickle outside the country, and who in general don't seem to have much of an idea how to not get shafted by the private sector they profess to love so much, so it shouldn't really be a surprise.
Anon 'cos I work in the public sector and frequently have to have fights with senior people in my department who continually get it into their head that they need overpriced gizmos "for work purposes". (The current fad is replacing low-end laptops with top-end iPad 2s, even though the laptops barely get used and there's no case whatsoever for needing a tablet device...)