Okay, you already own the 1050 Ti. So three ways to go, lower price, current max performance or upgrade potential
Lower Cost
PCPartPicker part list:
https://pcpartpicker.com/list/ZqXzGf
Price breakdown by merchant: https://pcpartpicker.com/list/ZqXzGf/by_merchant/
CPU: Intel Core i3-7100 3.9GHz Dual-Core Processor ($116.99 @ SuperBiiz)
Motherboard: ASRock H170M Pro4 Micro ATX LGA1151 Motherboard ($60.98 @ Newegg)
Video Card: EVGA GeForce GTX 1050 Ti 4GB SC GAMING ACX 2.0 Video Card ($144.99 @ B&H)
Total: $322.96
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-02-22 10:37 EST-0500
Max Performance
PCPartPicker part list:
https://pcpartpicker.com/list/zvhwHN
Price breakdown by merchant: https://pcpartpicker.com/list/zvhwHN/by_merchant/
CPU: Intel Core i5-7500 3.4GHz Quad-Core Processor ($196.33 @ OutletPC)
Motherboard: ASRock Z170M Extreme4 Micro ATX LGA1151 Motherboard ($101.98 @ Newegg)
Video Card: EVGA GeForce GTX 1050 Ti 4GB SC GAMING ACX 2.0 Video Card ($144.99 @ B&H)
Total: $443.30
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-02-22 10:39 EST-0500
Upgrade Potential
PCPartPicker part list:
https://pcpartpicker.com/list/yDTgKZ
Price breakdown by merchant: https://pcpartpicker.com/list/yDTgKZ/by_merchant/
CPU: Intel Core i3-7100 3.9GHz Dual-Core Processor ($116.99 @ SuperBiiz)
Motherboard: Gigabyte GA-Z270X-Gaming 5 ATX LGA1151 Motherboard ($180.91 @ Newegg)
Video Card: EVGA GeForce GTX 1050 Ti 4GB SC GAMING ACX 2.0 Video Card ($144.99 @ B&H)
Total: $442.89
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-02-22 10:34 EST-0500