550$ gaming build

Solution
PCPartPicker part list: http://pcpartpicker.com/p/dt9Tyc
Price breakdown by merchant: http://pcpartpicker.com/p/dt9Tyc/by_merchant/

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($98.89 @ OutletPC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($24.89 @ OutletPC)
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+ Motherboard ($83.89 @ OutletPC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($39.99 @ Newegg)
Storage: Seagate 2TB 3.5" 7200RPM Hybrid Internal Hard Drive ($89.99 @ Amazon)
Video Card: Gigabyte Radeon R9 390 8GB SOC Video Card ($263.99 @ Newegg)
Case: Rosewill CHALLENGER ATX Mid Tower Case ($29.99 @ Newegg)
Power Supply: Antec High Current Gamer 620W 80+ Bronze Certified...
Well if you factor in the GPU and Operating system it's going to cost you more than what you have in that list. What you can do is go with an i3 to drop the cost and upgrade to an i5 (non-K is fine for gaming) later.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4130 3.4GHz Dual-Core Processor ($108.99 @ SuperBiiz)
Thermal Compound: Arctic Cooling MX4 4g Thermal Paste ($5.89 @ OutletPC)
Motherboard: Gigabyte GA-H81M-S1 Micro ATX LGA1150 Motherboard ($41.99 @ SuperBiiz)
Memory: Mushkin Silverline 8GB (2 x 4GB) DDR3-1600 Memory ($34.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($41.99 @ SuperBiiz)
Video Card: MSI GeForce GTX 750 Ti 2GB Video Card ($107.99 @ SuperBiiz)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($30.99 @ SuperBiiz)
Power Supply: SeaSonic S12II 430W 80+ Bronze Certified ATX Power Supply ($48.99 @ SuperBiiz)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer ($12.99 @ Newegg)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($94.89 @ OutletPC)
Case Fan: Antec TriCool 75022 34.0 CFM 80mm Fan ($6.99 @ Amazon)
Monitor: Asus VS228T-P 60Hz 21.5" Monitor ($96.99 @ NCIX US)
Keyboard: Cooler Master CM Storm Devastator Gaming Bundle Wired Gaming Keyboard w/Optical Mouse ($23.99 @ SuperBiiz)
Other: gpu ($90.00)
Total: $747.67
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-09-30 23:49 EDT-0400

Without the video card and operating system this would cost you $543; but since you want to game I would recommend minimum i3 and a GTX 750Ti for medium/low settings at 1080p 30-40FPS. I would drop the case fans on this.
 
Do you need monitor, keyboard and mouse? It may seem like a bit much, but if you need a monitor then you may want to add 100 to 150 dollars to the budget. Getting a computer with monitor for 550 dollars would be a SEVERE downgrade from what 700 would get you.
 
Assuming no monitor.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4130 3.4GHz Dual-Core Processor ($108.99 @ SuperBiiz)
Motherboard: MSI H81M-E35 V2 Micro ATX LGA1150 Motherboard ($54.99 @ SuperBiiz)
Memory: Kingston HyperX Fury Black 8GB (2 x 4GB) DDR3-1866 Memory ($38.99 @ SuperBiiz)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.95 @ SuperBiiz)
Video Card: MSI GeForce GTX 950 2GB Video Card ($154.99 @ SuperBiiz)
Case: NZXT S340 (Black) ATX Mid Tower Case ($63.99 @ SuperBiiz)
Power Supply: SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply ($44.99 @ Newegg)
Total: $514.89
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-01 01:18 EDT-0400
 
Only build without other externals:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4170 3.7GHz Dual-Core Processor ($111.99 @ NCIX US)
Motherboard: ASRock H97M Anniversary Micro ATX LGA1150 Motherboard ($61.98 @ Newegg)
Memory: Crucial Ballistix Sport 8GB (2 x 4GB) DDR3-1600 Memory ($37.99 @ Amazon)
Storage: Kingston SSDNow V300 Series 120GB 2.5" Solid State Drive ($43.99 @ SuperBiiz)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($41.99 @ SuperBiiz)
Video Card: EVGA GeForce GTX 950 2GB Superclocked+ ACX 2.0 Video Card ($155.20 @ Newegg)
Case: Thermaltake Versa H22 ATX Mid Tower Case ($28.99 @ SuperBiiz)
Power Supply: SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply ($49.99 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.45 @ OutletPC)
Total: $548.57
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-01 04:34 EDT-0400
 
PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($98.89 @ OutletPC)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler ($19.98 @ OutletPC)
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+ Motherboard ($83.89 @ OutletPC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($44.89 @ OutletPC)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.89 @ OutletPC)
Video Card: Asus GeForce GTX 960 4GB Video Card ($199.96 @ Newegg)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($35.99 @ SuperBiiz)
Power Supply: SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply ($44.99 @ Newegg)
Total: $578.48
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-02 20:11 EDT-0400

When the FX 6300 is overclocked this will perform better than the i3 in almost every scenario. Game performance will be better again because of the more powerful graphics card .
OCing is very easy using AMD's software .
If I had another $60 to spend I would want an SSD but that wont improve game performance . Just loading and booting times
 


thanks could you build me one with a ssd or better gpu, dont worry about the price.
 
PCPartPicker part list: http://pcpartpicker.com/p/dt9Tyc
Price breakdown by merchant: http://pcpartpicker.com/p/dt9Tyc/by_merchant/

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($98.89 @ OutletPC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($24.89 @ OutletPC)
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+ Motherboard ($83.89 @ OutletPC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($39.99 @ Newegg)
Storage: Seagate 2TB 3.5" 7200RPM Hybrid Internal Hard Drive ($89.99 @ Amazon)
Video Card: Gigabyte Radeon R9 390 8GB SOC Video Card ($263.99 @ Newegg)
Case: Rosewill CHALLENGER ATX Mid Tower Case ($29.99 @ Newegg)
Power Supply: Antec High Current Gamer 620W 80+ Bronze Certified Semi-Modular ATX Power Supply ($59.99 @ Newegg)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer ($12.99 @ Newegg)
Total: $704.61
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-03 03:11 EDT-0400
 
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