In lieu of a real post, please enjoy a taste of The Sandbaggers, a brilliant spy show from the 1970s on British television. It shows you what you can do with pretty much zero budget – great writing and actors who absolutely believe in their roles combine to create the most tension I've seen outside of Hitchcock, and these episodes whip along at a speed that Peter Hunt would be proud of.
The Ipcress File was marketed at the anti-Bond, and yes, it's cool in an unBondian way. But The Sandbaggers is the real deal – spies risking their lives in the midst of bureaucracy and politics. Pretty much, I think you'd have to say, the way it is.
No one has ever come close to Ian Mackintosh's vision on this kind of budget, before or since.