You seem to have a slight misunderstanding of real life. You have zero right to any information, as it forms part of a commercial agreement between DPA and the supplier, and their subcontractors. If DPA is happy with it, that's all that matters - and after all, someone at DPA ultimately has to answer for how they spent the budget to their superiors, who answer to Parliament, who answer to YOU. The National Security argument also holds - any detailed cost breakdown will by necessity give more than enough detail to give all sorts of clues about capability, which is protected information.
The exact same situation will apply to ANY commercial agreement - just because (for example) you were a shareholder in Apple it wouldn't give you the right to know anything about the development and manufacturing costs of an iPod, you just have to accept that it costs what it costs, and that the people paying for the iPod to be built (Apple) will get the best deal out of the contracted manufacturer based on their knowledge of the processes involved, and the submitted bid.
As for talking bollox/crap/shit - bit of a harsh judgment given you know absolutely nothing of the source you're questioning. You'll obviously never learn to trust any sources without independent citation, or any facts without sources. This is the Wikipedia disease; sometimes you have to accept that people might actually have some clue of what they're talking about based on their personal experience.
It might be nice to hand out figures - assuming someone had them immediately to hand - but why would they? If they aren't officially released you'd never trust them anyway. And anyone who leaked them would find that a career-limiting move. They might even wake up one morning to a man standing on their doorstep, writ in hand...
And even then, would you have any idea on how to interpret the data? Assuming, for example, that the cost breakdown included xxx antenna modules for the SAR at £xxK each, and the cost breakdown included the cost of the design work (xxx hours at £xx per hour), the raw gold plated alumina substrates, etching the substrates (plus the tooling), machining the substrates, microwave semiconductors, wire-bonding operations to mount the components on the substrates, the test and QA, machining the module casing from aluminum billet, gold-plating the casing, assembling the module, doing a full temperature sweep RF test etc. etc. - unless you have experience in the area how do you know if it's expensive, cheap, or just right? The same goes for all the rest of it.
Of course, whatever you got would never be enough to satisfy a professional cynic - a mind has been made up and nothing can change it. Blah blah waste of money blah blah buy from America blah blah schools/hospitals/poor troops is going to be refrain even if you could prove the kit was half the price, twice as capable, was just what everyone wanted and provided a cure for cancer as a side benefit.
Do I actually give a shit though? Not really, this program has nothing to do with me in any way, I know that I'll end up paying just as much tax however much is wasted on it, I don't care what the ultimate outcome is, or anything else. I just get pissed off when the whole overpriced/buy American/waste of money thing comes around again and again from people who really don't have a clue, and can't even justify it based on past military experience and trying to sell a book.