Some of the parts in your list are quite outdated, so not sure if this is due to a specific deal you're getting.
If not, then for heavy multitasking like YouTube channel content creation is likely to involve, streaming, etc.....you could look to the new Ryzen processors in your budget range:
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD RYZEN 7 1700 3.0GHz 8-Core Processor ($328.99 @ SuperBiiz)
Motherboard: Asus PRIME B350M-A Micro ATX AM4 Motherboard ($89.99 @ B&H)
Memory: G.Skill Ripjaws V Series 16GB (2 x 8GB) DDR4-3200 Memory ($108.99 @ Newegg)
Storage: Samsung 960 Evo 250GB M.2-2280 Solid State Drive ($129.99 @ B&H)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.33 @ OutletPC)
Video Card: EVGA GeForce GTX 1080 8GB FTW DT GAMING Video Card ($519.99 @ Amazon)
Case: Deepcool DUKASE V2 ATX Mid Tower Case ($54.99 @ B&H)
Power Supply: EVGA SuperNOVA G3 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($78.99 @ SuperBiiz)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($89.99 @ NCIX US)
Total: $1451.25
Prices include shipping, taxes, and discounts when available
Or you could look to Intel for a bit better maximum frame-rate in some games (though probably not perceptibly faster), at the expense of not being nearly as capable at multi-threaded tasks:
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i7-7700K 4.2GHz Quad-Core Processor ($338.77 @ OutletPC)
CPU Cooler: Deepcool GAMMAXX 400 74.3 CFM CPU Cooler ($24.88 @ OutletPC)
Motherboard: Asus Z170-E ATX LGA1151 Motherboard ($127.99 @ SuperBiiz)
Memory: G.Skill Ripjaws V Series 16GB (2 x 8GB) DDR4-3200 Memory ($108.99 @ Newegg)
Storage: Samsung 960 Evo 250GB M.2-2280 Solid State Drive ($129.99 @ B&H)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.33 @ OutletPC)
Video Card: EVGA GeForce GTX 1080 8GB FTW DT GAMING Video Card ($519.99 @ Amazon)
Case: Deepcool DUKASE V2 ATX Mid Tower Case ($54.99 @ B&H)
Power Supply: EVGA SuperNOVA G3 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($78.99 @ SuperBiiz)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($89.99 @ NCIX US)
Total: $1523.91
Prices include shipping, taxes, and discounts when available