How much should I spend on a Gaming PC?

I was thinking of around the £500 mark. I'm not a graphic fanatic, and I would mostly play games such as Minecraft, Skyrim and Source games. As I have already stated that graphics aren't a major selling point to me, so playing Crisis 3 and Battlefield 4 and making them out as well a making them look nice and perform their best i not a major priority.

So basically for £500 I think that I could get a competent PC to play a variety of not so highly demanding games. Am I right?

I'm already equipped with a mouse, keyboard etc.

Added (1). Line 3: The first 'making' should be 'maxing'

I would go in between the 500-600$ range. I believe that's about 400-500 euros. You'll be able to get/build a PC that will allow you to play almost any game.

If you want to be PC Master Race you need i7 intel, GTX 760, and at least 8 GB of RAM

It is not that easy. You first have to find a PC that will play the game(s) you want. Not every PC has the resources to run a decent game.
Example for "Skyrim" you need a machine that at least has the following hardware, anything less will make for a poor gaming experience:
Skyrim Specs: (Video Graphics is where most machines fail the test)
Recommended
-Windows 7/Vista/XP PC (32 or 64 bit)
-Quad-core Intel or AMD CPU processor
-4GB System RAM
-6GB free HDD (Hard disk drive) space
-DirectX 9.0c compatible NVIDIA or AMD ATI video card with 1GB of RAM: Nvidia GeForce GTX 260 or higher; ATI Radeon HD 4890 or higher
-DirectX compatible sound card
-Internet access for Steam activation