What budget would you want for this?

I was just looking at the last couple posts and that would probably run higher than that. Should the cost include monitors, keyboard, mouse?

If you are going  with two monitors the best experience would be to have them both be the same kind.

Here is an example of a build with some of the specs already mentioned http://pcpartpicker.com/p/27NPS
some of that stuff should probably be cut down to a more reasonable level for you to get anywhere near your pricepoint. What parts are most important to you?

Indeed this is a very tight budget. Especially since I'm convinced that the parts you should not compromise on are the PSU and the human interface devices (display, mouse, keyboard).

So let me say that I'm very, very pleased with my golden silent fanless PSU. It doesn't get hot to the touch despite being fanless, it's 500W with a platinum power efficiency rating and allows being used as a 650W PSU, but then the platinum rating doesn't apply. It's not expensive, either.

So after a display and a PSU that leaves you with like no money. Isn't that the kind of situation where the AMD APUs make sense? Decent graphics and processor in a single package, so you don't have to live with intel GPU performance and still don't need a dedicated graphics cards. I'd look for price of the APU/mainboard combo first and invest what's left in RAM. That could still be recycled on an upgrade. HDD and especially SSD prices will probably drop so much that investing here doesn't make any sense.

That's quite some can of worms to open. Before you know what happened you have a garage full of electronic junk and a power bill that makes you weep.

@Street I find it odd that you acknowledge the price/perf advantage on AMD/Nvidia, but not on AMD/Intel.

Well for starters AMD GPUs are actually made by former ATI engineers, and you can consider that it's not the same branch. I have an AMD 7970 and it's quite powerful and far cheaper than the equivalent from Nvidia as far as benchmarks go. On the other hand a quad core i5 ROFLPWNs an eight core AMD FX and it's not that much more expensive here so yeah... IMO the difference in price is not what should make you choose an AMD over an Intel. Plus now the IGP is no longer an argument as the one in Haswell CPUs is pretty good from what I heard.

Here it's €200 vs 130 to 180. But the lower end ones are not even able to compete.

Ya I'd personal agree with you on trying windows, but Linux is open to editing. He can do whatever he wants to it. AKA programmers dream, if you can figure out how to use it well and/or compensate for the lack of game releases on it. (But hey that's what Virtual Machines are for right?)