PCPartPicker part list /
Price breakdown by merchant
CPU: Intel - Core i5-8600K 3.6GHz 6-Core Processor ($279.89 @ B&H)
CPU Cooler: Cooler Master - Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($19.99 @ Newegg)
Motherboard: MSI - Z370 SLI PLUS ATX LGA1151 Motherboard ($141.98 @ Newegg)
Memory: G.Skill - Ripjaws V Series 8GB (2 x 4GB) DDR4-2133 Memory ($84.88 @ OutletPC)
Storage: Samsung - 850 EVO-Series 250GB 2.5" Solid State Drive ($89.99 @ Newegg)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($43.78 @ OutletPC)
Case: Corsair - Vengeance C70 (Black) ATX Mid Tower Case ($119.99 @ Amazon)
Power Supply: Thermaltake - 750W 80+ Gold Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Operating System: Microsoft - Windows 10 Home OEM 64-bit ($88.89 @ OutletPC)
Case Fan: Corsair - Air Series SP120 Quiet Edition (2-Pack) 37.9 CFM 120mm Fans ($32.34 @ OutletPC)
Total: $951.72
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-11-13 02:06 EST-0500
Basically your computer on the brand new Coffee Lake chipset for $50 more. You are asking for new retail on 3+ year old tech.
I wouldnt even be asking $900 if you literally threw in all the peripherals. For the entire package I would probably sell it for anything in the $600-650 range.