Price is EUR143.44 including shipping once VAT is removed. Typical retail price for these in Australia is over $300, with the best price I can find being $279 shipped: http://www.addictedtoaudio.com.au/AKG-K550-ClosedBack-Refere…
The K550 has one of the most open soundstages for a closed-back headphone in this price range, with very clean and accurate sound. It also has excellent build quality, although some people (with smaller heads?) may have issues with the fit. The imput impedance is 32 ohms, meaning these are very easy to drive without an amp.
Some reviews:
http://www.whathifi.com/review/akg-k550
http://www.soundandvisionmag.com/blog/2012/07/30/review-akg-…
http://www.headfonia.com/akgs-new-reference-the-k550/
http://www.innerfidelity.com/content/wonderfully-competent-a…
http://noblehifi.blogspot.com/2012/06/akg-k550-review.html
Is this K550 better than Sennheiser HD650?