My husband was (still has his xbox 360, and his PS3) a big console player - it's what works when you're in the military and moving around everywhere, but I have brought him to the Dark Side (PC Master Race!) and he plays more PC than console these days - but he IS looking at waiting for the xbox 1 to drop in price before even thinking about getting it. His xbox still works just fine for the games he plays.
That being said, my husband and I used newegg.com (they ship internationally - reasonably priced rates as well) and it has tutorials, and lots of videos on everything to help you pick the best components for your self-built PC.
Their prices are SUPER reasonable (and they even have refurbished items for 1/2 or 3/4 of the price WITH a guaranty) and we put together our monster gaming PC for about $700 (that's less than 600 Euro, I think) with some exceptional pieces (Graphics card, RAM) and just prioritised items and prices depending on what fitted with the goal of our PC: Purely gaming, nothing else.