I've spoken before about how the local grass-roots Drupalcamps are arguably the best value for money you can get, and I think that's still true. In fact, the three reasons given to go to DCA, also apply to camps to some extent. But there's nonetheless an atmosphere at a Drupalcon that I don't think can be broken up into camp-sized chunks and absorbed that way (much as the Drupalcamp atmosphere can't be purchased in bulk at a 'con.)
My first Drupalcon was in Paris, nearly five years ago. Even though I went with a colleague, I remember that I still felt somewhat trepidatious at being in a crowd of Europe's most committed Drupalers: impostor syndrome writ large, if you like. But I needn't have worried. I joined a kind, generous, supporting network of people that seemed geared up to include anyone who came to them with good intentions and a desire to learn more. It's uncanny, looking back, to appreciate that several of the people that I thought were big players in that social scene (largely Drupal UK people) were themselves at their very first Drupalcon, and had simply, rapidly become accepted as part of the group, all Drupalers together.
So in response to the question "should I go to Drupalcon Amsterdam?" I can only say: if you need to ask that question, then almost certainly yes, at least once! They're always a great experience: expensive, sure, but nothing quite beats the feel of a Drupalcon. While I might not go (or indeed be able to afford to go) every year, it still looks like DCA is worth it, especially for western-Europe Drupalers who find it almost on their doorstep. And if you needed any more motivation to go, bear in mind that earlybird tickets save you €75, so you should buy your ticket now, before Friday 11 July!