A Sub-$700 build help!

Here are some current sub $800 rigs in your range, that may have similar or better value around holiday shopping season:

AMD:

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

CPU: AMD FX-8300 3.3GHz 8-Core OEM/Tray Processor ($114.99) <- Tiger Direct
CPU Cooler: Cooler Master Hyper TX3 54.8 CFM Sleeve Bearing CPU Cooler ($15.99 @ Newegg)
Motherboard: ASRock 970M PRO3 Micro ATX AM3+/AM3 Motherboard ($39.98 @ Newegg)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($36.00 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($45.99 @ SuperBiiz)
Video Card: PowerColor Radeon R9 390 8GB PCS+ Video Card ($274.99 @ Newegg)
Case: Cougar Spike MicroATX Mini Tower Case ($33.99 @ SuperBiiz)
Power Supply: Antec HCG M 850W 80+ Bronze Certified Semi-Modular ATX Power Supply ($69.99 @ Newegg)
Optical Drive: LG GH24NSC0B DVD/CD Writer ($12.99) <-with newegg email promotion coupon code
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($89.99) <-with newegg email promotion coupon code
Total: $734.90
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-06 23:52 EDT-0400

Intel/Nvidia:

PCPartPicker part list: http://pcpartpicker.com/p/jzR4bv
Price breakdown by merchant: http://pcpartpicker.com/p/jzR4bv/by_merchant/

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor ($175.88 @ OutletPC)
Motherboard: ASRock Z97M Anniversary Micro ATX LGA1150 Motherboard ($62.98 @ Newegg)<-Z97 because $5 less than H97 currently
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($36.00 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($45.99 @ SuperBiiz)
Video Card: EVGA GeForce GTX 970 4GB Superclocked ACX 2.0 Video Card ($299.99 @ NCIX US)
Case: Rosewill CHALLENGER ATX Mid Tower Case ($30.00 @ Newegg)
Power Supply: SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply ($44.00 @ Newegg)
Optical Drive: LG GH24NSC0B DVD/CD Writer ($12.99)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($89.99)
Total: $797.82
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-07 00:14 EDT-0400

If you're anywhere within ~few hours of a MicroCenter:

http://www.microcenter.com/site/products/amd_bundles.aspx

I'd BF there. You should be able to get a FX8320/mobo combo for $120 and a 390 for ~$270....and that gets you most of the way to the price point:

PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-8320 3.5GHz 8-Core Processor ($139.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler ($19.98 @ OutletPC)
Motherboard: Asus M5A99FX PRO R2.0 ATX AM3+ Motherboard ($106.99 @ Newegg)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($51.99 @ Newegg)
Storage: Kingston SSDNow V300 Series 120GB 2.5" Solid State Drive ($47.99 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($45.99 @ SuperBiiz)
Video Card: Gigabyte Radeon R9 390 8GB SOC Video Card ($309.99 @ Amazon)
Power Supply: Corsair CSM 750W 80+ Gold Certified Semi-Modular ATX Power Supply ($74.99 @ Newegg)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($93.75 @ OutletPC)
Total: $891.66
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-07 00:10 EDT-0400

Can also shop this, but may not get as big a discount:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4370 3.8GHz Dual-Core Processor ($144.99 @ SuperBiiz)
Motherboard: ASRock H97M PRO4 Micro ATX LGA1150 Motherboard ($79.89 @ OutletPC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($44.99 @ Amazon)
Storage: Kingston SSDNow V300 Series 120GB 2.5" Solid State Drive ($47.99 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($45.99 @ SuperBiiz)
Video Card: EVGA GeForce GTX 970 4GB Superclocked ACX 2.0 Video Card ($299.99 @ NCIX US)
Case: Xion XON-560 MicroATX Mini Tower Case ($35.98 @ Newegg)
Power Supply: Corsair CSM 650W 80+ Gold Certified Semi-Modular ATX Power Supply ($69.49 @ Newegg)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($93.75 @ OutletPC)
Total: $863.06
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-10-07 00:15 EDT-0400