Typhoon actually does have a place
I'm an ex-RAF engineering officer, so I have some credentials here. And in my opinion Typhoon does have a place, albeit the cost overruns are painful. Firstly to deal with the cost, the US have spent a lot more per plane on previous development projects (take stealth for example). Unfortunately, when you are the first people using a new jet, and you filter in all the development costs of that jet, it seems expensive. Take a look again in 10 years when a bunch of other people have bought the jet, and the development costs have been spread around a bit more.
Now, look at the capabilities of the jet. Eurofighter/Typhoon was always designed to be a multi-role aircraft. Although the mistakes of the Tornado (F3 not really that great) meant that they pushed hard to get a decent modern fighter. Typhoon is definitely a decent modern fighter. Right from the start, Typhoon was supposed to replace both the Tornado F3 and the Jaguar. The Jaguar was essentially used as a bomber more than anything else, so the Typhoon was always needed multi-role. The Typhoon does not replace the Tornado GR4 though, so we still have a deep penetration bomber capability. Now, many people have claimed in recent years that we don't need a modern fighter in the RAF. I have to point out that these people don't have a clue what they are talking about. In a number of the wars that Britain has fought in living memory we have needed fighters. We suffered greatly in the Falklands War because the only fighters we had were a handful flying off through-deck cruisers (rather than real fighters off an aircraft carrier). In Gulf War 1 if Saddam had actually used his air force rather than flying it all to Iran, we would have had a much harder time in the first weeks of the war. Saddam had over 500 modern aircraft that were perfectly capable of mixing it up with Allied aircraft. We were lucky there, and our luck might well run out with North Korea, Iran, or anyone else we pick a fight with in the next 10-20 years.
Now, the cry these days seems to routinely be, "Buy American." Unfortunately, this isn't such a great cost saving as it might seem. One of the most important things to remember here is that America does not sell top end avionics fits to anyone, including it's allies. Anyone who has worked with, or studied aircraft will tell you that the avionics fit in modern battle is the single most important thing. Since weapons delivery these days is usually stand-off, the avionics fit is more important than say agility in a fighter or the ability to fly undetected in a bomber. I've watched exercises where Tornado F3s have annihilated American top end aircraft simply because at the time the F3 avionics fit was better (JTIDS in particular). Despite the fact that the F3 has the turning circle of a battleship. If we went and bought American for our key air defence or bomber capabilities we would then spend vast amounts of money developing the avionics fit for them. The aircraft wouldn't look as great then would it? The avionics fit in Eurofighter is outstanding, we have paid a lot of money for it. It could be better in the air to ground role, something that I think will happen in Tranche 3. Finally, if you compare the cost of Eurofighter to the cost of buying an American jet, then developing our own avionics fit for it, the cost isn't that different.
Now, in logistics roles (Hercules/A400M or Chinook etc.) the arguments not to buy American are far weaker. Here I would be happy if we did go out and buy the new Hercules and Chinook. It would help our troops a lot, and probably save us a little money. But again, in the long run, it wouldn't necessarily save as much as you think, since the Americans will fleece us on spares and upgrades.