configuration advice

R7 265X or R7 270X and 4130 + 2x4 GB geil/corsair :)

How about a lower end AMD FX processor? Maybe even a Phenom if you can find one?

I believe it would give you more options to upgrade in the future, at least compared to the Athlon II X4 740 or 750k without switching out your mobo again. All of the FX processors use the AM3+ socket whereas the Athlon II X4 740 uses FM2.

Scroll down for socket FM2 compatible CPUs/APUs
Scroll down for socket AM3+ compatible CPUs

Much more room to upgrade with the AM3+ socket.

I have a FX 4130 in my PC. PC Partpicker says it's available at $100 (US price), or there is the Phenom II X4 945 at $80 (the 955 and 965 are also under $100). According to them the AMD Athlon II X4 740 is $75 and the 750k is $80 so there wouldn't be much difference in price, especially if you went for the Phenom.

the 750k +7770ghz are a good combo with low price, if you have money issues you can always go for an apu, 6600k/680k0 or 7000k series and lower the total value about 40 ~ 70 dollars(course i'm couting it with really good memory)

You might be able to run The Witcher 2 on low-medium spec. Having an i7-2600K, 8GB of RAM, and an HD 7770, I only managed medium settings. Since upgrading to an R9 270X though, my computer runs the game on Ultra flawlessly at around 50FPS, so the game's performance seems mostly dependent on your video card.

Personally, I'd get the i3-4130, because it mostly wipes the floor with AMD-CPUs, unless the game uses 4 - 6 Threads, which still is fairly uncommon. But the 750K option might be a cheaper one. Much more important, especially in this budget range, is the graphics card.

Depending on where you live and how the prices are there, get as much graphics card performance as possible. Instance: If you can get the 750K and a hd7870 (or equivalent) instead of a 4130 and a hd7770, go for the weaker CPU with the better GPU.

Regardless of the budget, you should at least get an hd7790. Is usually costs like 10% more than the HD7770, but also boasts a 15% performance increase. An HD7790 will run every game you throw at it in decent settings on your monitor's native resolution.

Also you left out a very important detail: Which motherboards are you looking to buy? Often you can save money on those.

30% more? Sounds like Brazil... About the mobo i like gigabyte better than asus, its about price, and when i got my setup i didnt take any overclock plans over so the asus features not worked for me, since the value of an asus here is about 30/40% higher than a gigabyte or a ecs i took it, the i finally got me an nero 3 air cooler and 1 hd 7750, i could say that apus are a good choice for slow setups, since they have a good price/performance and keep a good upgrade scale opened.

ok thats all i got, so if you go for apu just remmember to take the best memory avaliable, i mean it, the apu runs like a beast with higher memorys, if you go after the 750k or the I3 make sure to buy a good vga, have fun, building a pc is very trick but also quite satisfactory.
Ah yes, sorry about the english, its not my first language.

Why not an FX-6300? cost 5€ more than the i3 4130, FX-6300 is one of the best for the money, and AMD under 80€ MOBOs offer more features that the intel one's, combining FX-6300 with a good priced MOBO will make you the same cost as this i3 + intel's MOBO, and for GPU 7770 is a good choice there are a lot for cheap priced from good brands with 1Gb VRAM, or better a GTX 750 or Radeon HD 7790 if you spend more.