You will want faster RAM if you are building with Ryzen. You could probably drop to 8gb of RAM if you wanted to save some money and you would likely not miss much in performance. I would also suggest dropping to the 1400 as it can OC to the 1500x level just the same. I would also suggest getting a SSD as a boot drive. I would not build a PC today without an SSD for the OS.
PCPartPicker part list:
https://pcpartpicker.com/list/FzvBtJ
Price breakdown by merchant: https://pcpartpicker.com/list/FzvBtJ/by_merchant/
CPU: AMD - Ryzen 5 1400 3.2GHz Quad-Core Processor ($165.87 @ OutletPC)
Motherboard: MSI - B350M GAMING PRO Micro ATX AM4 Motherboard ($78.88 @ OutletPC)
Memory: G.Skill - Ripjaws 4 Series 16GB (2 x 8GB) DDR4-3000 Memory ($119.89 @ OutletPC)
Storage: Kingston - A400 240GB 2.5" Solid State Drive ($84.89 @ OutletPC)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.33 @ OutletPC)
Video Card: EVGA - GeForce GTX 1050 Ti 4GB ACX 2.0 Video Card ($122.76 @ Jet)
Power Supply: EVGA - SuperNOVA NEX 650W 80+ Gold Certified Fully-Modular ATX Power Supply ($70.89 @ OutletPC)
Operating System: Microsoft - Windows 10 Home OEM 64-bit ($87.89 @ OutletPC)
Total: $779.40
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-05-26 10:39 EDT-0400